astralavista

Liquid Ice

2006-11-04T13:22:00.000-05:00

Scientists at the Sandia National Laboratory in New Mexico have squeezed a diamond so hard that it turned into a pool of liquid. The herculean grip came courtesy of huge magnetic fields generated by Sandia's monumetal "Z Machine."

The Z Machine is a powerful energy booster designed to approach conditions required for nuclear fusion by employing traditional energy sources. The machine uses wall-current electricity to charge giant capacitor banks. The capacitors then connect via gargantuan cable tentacles to a vacuum chamber, 10 feet in diameter and 20 feet high.

Sandia said that when the accelerator fires "highly synchronized laser-triggered switches allow the stored energy to be discharged simultaneously through the 36 cables, each as big around as a horse and 30 feet long, arranged like spokes of a wheel and insulated by water. The enormous electrical pulse of 50 trillion watts strikes a complex target about the size of a spool of thread." The result is pressure equivalent to 10 million times the atmospheric pressure at the sea level.

(In something of an anticlimax, the scientists did not name the machine Z after, say, the awesome thunder-throwing god Zeus, but because the current passing directly into the target travels vertically.)

Sandia reported that most recently scientists at the lab turned the crushing pressure on a diamond sheet. Powerful magnetic waves generated by the Z were hitting the diamond target at 20 times the speed of a rifle bullet and turned it into a liquid. "At the pressures we're interested in, everything is compressible," shrugged Mark Herrmann, a Sandia researcher.

Sandia said that the object of the experiment was to better understand the behavior of fuel pelets that may in the future power a fusion reaction. The lab also said that the "results of the fusion reaction also will be used to validate physics models in computer simulations used to certify the safety and reliability of the US nuclear weapons stockpile."

Image: Electrical discharges illuminate the surface of the Z machine, the world's most powerful X-ray source. Photo by Randy Montoya. Sandia.

The Odd Couple

2006-08-13T08:41:00.000-04:00

Scientists have long believed that our baby solar system looked something like a fried egg: the yolk of the Solar orb in the center a flat disc of of gas and dust from which the planets were forming.
Now this model got a little scrambled. Scientists at the university of Toronto and the European Space Observatory in Chile have observed two massive planet-like objects called "planemos" orbiting each other on their journey through space.
Pairs of stars orbiting each other are quite common. (The dog days of August are named after the dog star Sirius, one of the brightest objects in the late summer sky, which in fact is a system of two stars spinning around each other.) However, a pair of planemos orbiting in a similar fashion has never been seen.
"Their mere existence is a surprise, and their origin and fate a bit of a mystery," said Ray Jayawardhana, an associate professor of astronomy and astrophysics at the University of Toronto. Jayawardhana and his colleague Valentin D. Ivanov of the European Southern Observatory report the discovery in the August 3 issue of Science Express.
The planemos in question are quite chunky. The smaller one is seven times as large as Jupiter, the biggest planet in the Solar system, the other one is twice its size. But the scientists wrote that "both objects have masses similar to those of extra-solar giant planets, usually found in orbit around a star."
Jayawardhana and Ivanov wrote that he newborn pair is barely a million years old. The planemos are staring at each other across a vast cosmic chasm some six times the distance between the sun and Pluto wide. They are located in the Ophiuchus star-forming region approximately 400 light years away.
"Roughly half of all sun-like stars, and about a sixth of brown dwarfs, come in pairs," Jayawardhana said . Brown dwarfs are moribund stars that weigh less than 75 Jupiter masses. Their mass is not sufficient to ignite and sustain nuclear fusion, and burn like a regular star.
The Toronto team wrote that the "existence of this wide pair poses a challenge to a popular theory which suggests that brown dwarfs and planemos are embryos ejected from multiple proto-star systems. Since the two objects in...are so far apart, and only weakly bound to each other by gravity, they would not have survived such a chaotic birth."
Jayawardhana and Ivanov said that planets are thought to form out of disks of gas and dust that surround stars, brown dwarfs and even some planemos. They believe that "these planemo twins formed together out of a contracting gas cloud that fragmented, like a miniature stellar binary.
"We are resisting the temptation to call it a 'double planet' because this pair probably didn't form the way that planets in our solar system did," says Ivanov. "Now we're curious to find out whether such pairs are common or rare. The answer could shed light on how free-floating planetary-mass objects form."

Living On The Edge

2006-06-10T09:24:00.000-04:00

Ever ponder the precariousness of life. Here's an image to stir up your thoughts. Somehow, improbably, life has evolved in the Milky Way, a galaxy similar to
this one captured so beautifully by the Hubble Space Telescope. Here we are, suspended in space, anchored to a dusty island of 100 million stars, which together don't amount to much more but a cosmic comma.

The galaxy in the picture is clumsily called NGC 5866. It floats in space in the constellation Draco, some 44 million light years away. It is some 60,000 light years in diameter, about two-thirds the size of the Milky Way. But it has the same mass, suggesting that it may be much denser.

The Hubble image shows the galaxy, which is tilted nearly edge on to us, as a crisp dust lane. The Hubble team said that the picture "highlights the galaxy's structure: a subtle, reddish bulge surrounding a bright nucleus, a blue disk of stars running parallel to the dust lane, and a transparent outer halo."

The team said that NGC 5866 is a disk galaxy of type "S0" (pronounced s-zero). "Viewed face on, it would look like a smooth, flat disk with little spiral structure," the astronomers said. "It remains in the spiral category because of the flatness of the main disk of stars as opposed to the more spherically rotund (or ellipsoidal) class of galaxies called "ellipticals." Such S0 galaxies, with disks like spirals and large bulges like ellipticals, are called 'lenticular' galaxies."

The Hubble team said this image of NGC 5866 is a combination of blue, green and red observations taken with the Advanced Camera for Surveys in February 2006.

Credit: NASA, ESA, and The Hubble Heritage Team (STScI/AURA)

Evening On Enceladus

2006-03-07T18:17:00.000-05:00

Courtesy of NASA: Enceladus hangs like a single bright pearl against the golden-brown canvas of Saturn and its icy rings. Visible on Saturn is the region where daylight gives way to dusk. Above, the rings throw thin shadows onto the planet. Icy Enceladus is 505 kilometers (314 miles) across.

Image credit: NASA/JPL/Space Science Institute

Can You Hear Me Now?

2006-02-02T11:33:00.000-05:00

Don't get alarmed tomorrow night if you look up at the sky (with a suffiently powerful telescope) and see a man drifting between the stars. Blame it on the Russians. For Feb. 3 is the launch date of one of the strangest experiments in the history of space science. Cosmonauts flying the International Space Station will throw overboard an empty Russian space suit rigged with batteries, a radio transmitter, and an array of thermal and other sensors to monitor the impact of cosmic radiation, solar rays, and temperature on the empty shell. "SuitSat is a Russian brainstorm," said Frank Bauer of NASA's Goddard Space Flight Center. "Some of our Russian partners ... had an idea: Maybe we can turn old space suits into useful satellites."
SuitSat, as the project is called, is the first test of that idea.Transmissions from the suit will be beamed to Earth and anybody with a police scanner can listen in by tuning to the FM frequency of 145.990 MHz. It should remain in range for 5-10 minutes per orbit.(Check on NASA's JPass when the suit will be flying over your house. Use the same coordinates as for the ISS to find it.) The suit will stay in orbit for about 6 weeks before it tumbles and burns in the atmosphere. Go here for more info on SuitSat.

Image: Oleg Kulik, Cosmonaut (2003) at the Venice Biennale

Shadow Play

2005-12-14T21:24:00.000-05:00

Late in October, the Cassini probe exploring Saturn and it's immediate cosmic neighborhood snapped a beautiful image of Saturn's rings wrapping the planet's cloudy surface in a curved, striped sash of shadow and light. The resulting effect brings to mind a modernist lampshade, even a flying saucer. Note that some of the rings let some sunglight through, lending their shadow smoky translucency.
According to NASA, the three thin and bright arcs in this scene represent three well-known gaps in the immense ring system. From bottom to top here (and widest to thinnest) they are the Cassini Division, the Encke Gap and the Keeler Gap.
NASA said that the image was taken in infrared light (752 nanometers) using the Cassini spacecraft wide-angle camera on Oct. 29, 2005, at a distance of approximately 446,000 kilometers (277,000 miles) from Saturn. The image scale is 23 kilometers (14 miles) per pixel. The image was contrast enhanced to improve visibility of features in the atmosphere.

The Brains And The Bees

2005-12-11T17:51:00.000-05:00

In May 2004, an east Texas logger died after being stung hundreds of times by a swarm of bees. The Beekeepers' Association newsletter cited data from Texas A&M University, saying that bees have killed 15 Texans since 1991. But what if these deaths weren't just accidents? What if the bees had it in for the victims?
A team of European and Australian biologists just reported in the Journal of Experimental Biology that honeybees "can discriminate and recognize images of human faces."
The researchers were curious whether the ability to recognize faces was something only mammals could do. "There is evidence that the mammalian brain may have specialised neural circuitry for face recognition tasks, although some recent work questions these findings," they wrote in the abstract of their paper. "Thus, to understand if recognising human faces does require species-specific neural processing, it is important to know if non-human animals might be able to solve this difficult spatial task."
Apparently they do. They tested honeybees (Apis mellifera) to "evaluate whether an animal with no evolutionary history for discriminating between humanoid faces may be able to learn this task."
Here's what the team found out: "Using differential conditioning, individual bees were trained to visit target face stimuli and to avoid similar distractor stimuli from a standard face recognition test used in human psychology. Performance was evaluated in non-rewarded trials and bees discriminated the target face from a similar distractor with greater than 80% accuracy. When novel distractors were used, bees also demonstrated a high level of choices for the target face, indicating an ability for face recognition. When the stimuli were rotated by 180° there was a large drop in performance, indicating a possible disruption to configural type visual processing."

Image Credit: Smoky River Express, Caption: Area beekeepers (from left) Paul Benoit and Fernando Sanchez were brave during the Bee Beard Contest in last year's Honey Festival.

Seeing the Invisible

2005-12-10T23:07:00.000-05:00

Astronomers from Johns Hopkins University and the Space Telescope Science Institute in Baltimore, Md. have come up with the first detailed map of the mysterious dark matter, albeit one covering only a tiny patch of the sky.
Myungkook James Jee, Johns Hopkins researcher and co-author of the project, said that the team came up with the map by measuring the effects of gravitational lensing by dark matter on the images of two galaxy clusters taken by the Hubble Space Telescope.
Gravitational lensing is a visual effect postulated by Einstein's general theory of relativity. Any sufficiently massive body will cause a dimple in space-time and shift, distort, even multiply images of stars and galaxies hiding behind it like a fun-house mirror.
"The images we took show clearly that the cluster galaxies are located at the densest regions of the dark matter haloes, which are rendered in purple in our images," Jee said.
The astronomers also reported that dark matter has a ghost-like character where dark matter particles can pass through each other rather than bounce off and scatter like billiard balls as is common with ordinary matter. "Collision-less particles do not bombard one another, the way two hydrogen atoms do," said Jee. "If dark matter particles were collisional, we would observe a much smoother distribution of dark matter, without any small-scale clumpy structures."
The map appears in the December edition of the Astrophysical Journal.

Image: Snapshot of the computer simulation of the dark matter Universe. These filamentary structures are called "cosmic webs" of dark matter. Credit: Johns Hopkins University.

Polar Drift Not So Glacial

2005-12-09T10:04:00.000-05:00

After some 400 years of relative stability, Earth's North Magnetic Pole has moved nearly 1,100 kilometers out into the Arctic Ocean during the last century, scientists from Oregon State University reported. If it keeps going at the present clip, it will move from northern Canada to Siberia within the next half-century.
Besides the possibility that Alaskans, the Inuit and other natives of northern Norh America may loose the sight of the Northern Lights for many generations, the shift has implications for international travel and communications. The scientists said that radiation influx associated with our planet's magnetic field affects charged particles streaming down through the atmosphere can impact airplane flights and telecommunications.
"This may be part of a normal oscillation and it will eventually migrate back toward Canada," said Joseph Stoner, assistant professor at the university' s College of Oceanic and Atmospheric Sciences. "There is a lot of variability in the polar motion, but it isn't something that occurs often. There appears to be a 'jerk' of the magnetic field that takes place every 500 years or so. The bottom line is that geomagnetic changes can be a lot more abrupt than we ever thought."
The scientists said in a press release that calculations of the North Magnetic Pole's location from historical records goes back only about 400 years, while polar observations trace back to John Ross in 1838 at the west coast of Boothia Peninsula.
To look deeper in the past, the scientists drilled 5-meter core samples from the ice and 5,000 year old sediments deposited on the bottom of frozen Arctic lakes.
These sediments contain magnetic particles called magnetite, the scientists said. Much like a classroom experiment with magnets and iron filings, they record the the orientation of Earth's magnetic field at the time they were deposited. The team then used carbon dating and layer counting to determine approximately when the sediments were deposited and track changes in the magnetic field.
The Oregon team reported that "Earth last went through a magnetic reversal some 780,000 years ago. These episodic reversals, in which south becomes north and vice versa, take thousands of years and are the result of complex changes in the Earth's outer core. Liquid iron within the core generates the magnetic field that blankets the planet."
Because of that field, a compass reading of north in Oregon will be approximately 17 degrees east from 'true geographic north.' In Florida, farther away and more in line with the poles, the declination is only 4-5 degrees west."
The Northern Lights, which are triggered by the sun and fixed in position by the magnetic field, drift with the movement of the North Magnetic Pole and may soon be visible in more southerly parts of Siberia and Europe - and less so in northern Canada and Alaska."
No word on whether the southern magnetic pole is undergoing silimar shift.
One beguiling question also remains unaswered. Could it be the movement of Earth's crust that's actually sped up? After all, it was magnetite crystals recovered from basalts in Greenland in the 1960s that proved the movement of plate tectonics and pointed to the existence of Pangea, the mother of all continents.

Image Credit: University of Northern British Columbia

Bad Weather in the Perseus Cluster

2005-12-07T22:21:00.000-05:00

Call it the cosmic Katrina. The Perseus Cluster, some 250 million light years away from Earth, is a giant bundle of destruction shredding its cosmic neighborhood to gauzy wisps of interstellar dust.
The cluster has been wracked by some nasty cosmic "weather" for hundreds of millions of years. Now scientists from Harvard and NASA have trained their orbital Chandra X-ray observatory at the cluster for 270 hours for detailed observations.
They've reported that the cluster, which is one of the most massive objects in the universe, "contains thousands of galaxies immersed in a vast cloud of multimillion degree gas with the mass equivalent of trillions of suns." They also observed an entire galaxy that's being torn apart and cannibalized by its giant cousin, called Perseus A, residing at the center of the cluster. (See the dark blue filaments near the center of the image.)
Perseus A itself is spinning around a vicious black hole. Resembling a cosmic hurricane, the scientists spotted huge low pressure regions expanding outward 300,000 light years from the space warping singularity. "The plumes are due to explosive venting from the vicinity of the supermassive black hole," the scientists said.
They said that the venting produces sound waves which heat the gas throughout the inner regions of the cluster and prevent the gas from cooling and making stars at a high rate. "This process has slowed the growth of one of the largest galaxies in the Universe," they said. "It provides a dramatic example of how a relatively tiny, but massive, black hole at the center of a galaxy can control the heating and cooling behavior of gas far beyond the confines of the galaxy."
In the Greek mythology, Perseus was the son Zeus and Danae. Besides riding the winged horse Pegasus and liberating Andromeda, he's perhaps best remembered for chopping off Medusa's slithering head.

Monkey Madness

2005-08-11T22:11:00.000-04:00

Since it's summer and the weekend is coming up, here's a bit of brain candy for all of you Astralavista readers with too much time on your hands. The riddle comes courtesy of Radio Open Source, a great radio show put together by Boston's inimitable Christopher Lydon and available around the world via podcast. And yes, it apparently has a solution. Enjoy!

"A rope over the top of a fence has the same length on each side and weighs one-third of a pound per foot. On one end of the rope hangs a monkey holding a banana, and on the other end a weight equal to the weight of the monkey. The banana weighs 2 ounces per inch. The length of the rope in feet is the same as the age of the monkey, and the weight of the monkey in ounces is as much as the age of the monkey's mother. The combined ages of the monkey and its mother is 30 years. One-half the weight of the monkey plus the weight of the banana is one-fourth the sum of the weights of the rope and the weight. The monkey's mother is one-half as old as the monkey will be when it is three times as old as its mother was when she was one-half as old as the monkey will be when it is as old as its mother will be when she is four times as old as the monkey was when it was twice as old as its mother was when she was one-third as old as the monkey was when it was as old as its mother was when she was three times as old as the monkey was when it was one-fourth as old as its is now. How long is the banana?"

Image: deanhatescoffee.home.comcast.net

Milky Way Bulks Up

2005-08-11T06:31:00.000-04:00

New research published in the Astrophysical Journal shows that the Milky Way is likely much bigger than previously thought. Current estimates put its size at 100,000 light-years across. However, the new measurements show that our galaxy could be double the size.
The new data comes from precise measurements of our cosmic cousin, the spiral galaxy NGC 300, some 6 million light years away. Using an eight-meter telescope in Chile, the scientists made extremely sensitive measurements of faint stars residing on the galaxy's fringes. To their surprise, the faint stars went on and on, and finally tracing the edge of the galaxy at 47,000 light years from the galactic center, twice removed from where they thought it wash. "Our galaxy is much more massive and brighter than NGC 300," said Joss Bland-Hawthorn, astrophysics professor at the Anglo-Australian Observatory and the paper's lead author. "So on this basis, our Galaxy is also probably much larger than we previously thought - perhaps as much as 200,000 light-years across."

Planet X

2005-07-30T08:19:00.000-04:00

Call it the revenge of kooks. Many ufologists have long argued for the existence of a tenth planet beyond the orbit of Neptune. Calling it Nibiru, they said the planet harbored an advanced civilization whose cosmonauts visited the Sumerians on Earth some 4,500 years ago. The defended their claim, saying that we haven't yet spotted Nibiru becasue it had an eliptical, comet-like orbit banked steeply to the plane of the solar sytem.

Find a good hole to hide.

Today's New York Times reports on a newly discovered piece of rock in the far-out solar system that's possibly larger than Pluto. The new body orbits at a puzzling 44-degree angle to the rest of the solar system. Already, astronomers are wondering about the forces that have have kicked it so high up. Is the new body the solar system's tenth planet? Some scientists already started calling Xena. Or will the discovery make Pluto lose its rank as a planet and become a mere cosmic rock? We'll need to wait for answers.

From the Times:

"Astronomers announced yesterday that they had found a lump of rock and ice that was larger than Pluto and the farthest known object in the solar system. The discovery will probably rekindle debate over the definition of "planet" and whether Pluto still merits the designation.
Skip to next paragraph

The new object - as yet unnamed, but temporarily known as 2003 UB313 - is now 9 billion miles away from the Sun, or 97 times as far away as Earth and about three times Pluto's current distance from the Sun. Its 560-year elliptical orbit brings it as close as 3.3 billion miles. Pluto's orbit ranges from 2.7 billion miles to 4.6 billion.

The astronomers do not have an exact size for the new planet, but its brightness and distance tell them that it is larger than Pluto, the smallest of the nine known planets.

"It is guaranteed bigger than Pluto," said Michael E. Brown, a professor of planetary astronomy at the California Institute of Technology and a member of the team that made the discovery. "Even if it were 100 percent reflective, it would be larger than Pluto. It can't be more than 100 percent reflective.""

Image: Orbit of the mythical Nibiru comes via greatdreams.com

This Is Radio Saturn

2005-07-27T07:23:00.000-04:00

The Universe may be big and empty but it's certainly not silent. The cosmos is roaring with all kind of ruckus. Quasars emit massive beams of radio waves, and so do centers of galaxies, massive neutron stars and other exotic cosmic inhabitants.
But you don't need to be big and heavy to grind out radio signals. The solar system puts on a radio show, too, and astronomers have long been tuning in.
Scientists from the University of Iowa, using NASA's Cassini spacecraft, have now recorded two particularly cool and creepy samples from Radio Saturn. (Listen in here and here.)
The scientists said that the radio signals, which they called "Halloween sound track," are related to Saturn's auroras, or northern and southern lights.
The scientists also said that time on this recordings has been compressed and their frequencies down-shifted since the broadcasts were high above the audible frequency range.
The research was published in the current issue of the Geophysical Research Letters.
(For comparison, here's a recorded signal of Radio Jupiter.)

Image: The image corresponds with the first sample from Saturn. "It appears as though the three rising tones are launched from the more slowly varying narrowband emission near the bottom of this display," the scientists said. "If this is the case, it represents a very complicated interaction between waves in Saturn's radio source region, but one which has also been observed at Earth." Credit: NASA/JPL/University of Iowa

Sun Soaked

2005-07-23T16:05:00.000-04:00

Caltech planetary scientist Maciej Konacki has discovered the first planet that never sleeps. The Jupiter-sized planet in the constellation Cygnus belongs to a complex solar system dominated by three different suns. And while multiple stars have been known to circle around each other, astronomers have never seen a planet in such company.
The discovery raises serious questions about what we know about planet formation, a topic frequently discussed on this blog (see previous post.)
Here's why: Latest planet formation theories propose that planets coalesce from a wide protoplanetary dust disks, circling stars much like Saturn's rings. Newborn planets are then pulled inwards towards the parent star. Some are gobbled up by it, some are flung into space like a rock from a sling by the star's gravity, and some settle in stable orbits.
However, theory says, if the parent star is part of a multi-stellar system, the dusk disk formation gets disrupted by the competing gravitational pulls of the different stars, the disk grows too narrow, and planet formation breaks down.
"How that planet formed in such a complicated setting is very puzzling," Konacki said about his discovery. "If we believe that the same basic processes lead to the formation of planets around single stars and components of multiple stellar systems, then such processes should be equally feasible, regardless of the presence of stellar companions. Planets from complicated stellar systems will put our theories of planet formation to a strict test."
The system is about 149 light-years from Earth. The stars are about as close to one another as the distance between the Sun and Saturn.
"In other words, a viewer there would see three bright suns in the sky," Caltech said in a press release. "In fact, the sun that the planet orbits would be a very large object in the sky indeed, given that the planet's "year" is only three and a half days long. And it would be yellow, because the main star of HD 188753 is very similar to our own sun. The larger of the other two suns would be orange, and the smaller red."
Said Konacki: "The environment in which this planet exists is quite spectacular. With three suns, the sky view must be out of this world-literally and figuratively."

Image: This artist's animation shows the view from a hypothetical moon in orbit around the first known planet to reside in a tight-knit triple-star system. Credit: Nasa

Star Dust

2005-07-19T22:30:00.000-04:00

In science, as in life, things aren't always what they seem. Take planetary formation.

Back in April 1984, American planetary scientists Bradford Smith and Richard Terrile observed a nearby star called Beta Pictoris and made a startling discovery: for the first time they saw a huge disk of orbiting dust spreading from the star like the swirling skirt of a Russian peasant bride. "I was very, very excited," Terrile told astronomer Ken Croswell, who tells the story in his book Planet Quest. "You look at the fundamental questions of astronomy - the origin of the universe, the origin of life: those are the things that we really, deep down in our souls, want to know, the things that keeps us up at night. Here's a direct link to that," said Terrile.
"Everybody had this feeling that we understood how planets formed, from a flattened disk of material," he told Croswell. "But there was no real hard physical evidence - no picture that you can see. And suddenly, in this blazing, obvious thing, is this picture which is an absolutely classic example of exactly what we thought happened when stars and planets formed. It was a slap in the face that said: Wake up, don't you see what's going on all around you."

Now it looks like we'll need to take another one on the jaw before we figure out how planets form. For Terrile's giddy conjecture about their formation may have been a tad too optimistic. New evidence shows that some disks may just be barren pancakes of dust that will never give birth to any new world.

Scientists from the Harvard-Smithsonian Center for Astrophysics have just discovered a dust disk that is 25 million years old and shows no signs of planet formation. The finding contradicts accepted theory, which says that most protoplanetray disks last only a few million years and rarely longer than 10 million years. "Finding this disk is as unexpected as locating a 200-year-old person," the Center's Lee Hartmann said in a press release. "We don't know why this disk has lasted so long, because we don't know what makes the planetary process start," said his colleague Nuria Calvet.

The disk, which is almost 600 million miles wide, orbits two red dwarf stars located some 350 light years away in the constellation Taurus.

"The disk looks a lot different than most other disks we've seen. This disk looks a lot more evolved than those around younger stars," said Hartmann. "Most stars, by the age of 10 million years, have done whatever they're going to do. If it hasn't made planets by now, it probably never will."

While Hartmann remains pessimistic about the disks chances every bearing a planet, Calvet still gives it a fighting chance. "This disk still has a lot of gas in it, so it may still form giant planets," he said.

Hartmann and Calvet said they want to search for more old disks and find out why some disks survive so much longer than most others.

Said Calvet: "It's important to find more objects like this because they give us clues about the conditions that influence the formation of planets."

Hartmann and Calvet's research will be published in The Astrophysical Journal Letters

Hammer In The Sky

2005-07-13T07:07:00.000-04:00

Scientists studying massive explosions flaring from a neutron star some 50,000 light years away say the blasts could serve as a powerful new tool for probing the guts of these enigmatic cosmic beasts.
Neutron stars are the last rung on the ladder leading a collapsing star to a black hole. Astrophysicist Fred Zwicky, who have coined the name neutron star, was the first to calculate in the 1930s that gigantic internal pressures in such stars push electrons inside atomic nuclei where protons gobble them up to form neutrons. The density is so huge, some million billion grams per cubic centimeter, that it squeezes the failing star into a sphere with a diameter of just 12 miles. Yet despite further work by Oppenheimer, Wheeler and many others, seven decades after Zwicky's discovery neutron stars hold on to a lot of their mystery, with scientists trying to decipher the details their internal structure.
Now they may get some help from a powerful X-blasts emanating from the neutron star SGR 1806-20, which were recorded last December. Scientists from the University of California San Diego, Italy's National Institute of Astrophysics, Israel and the Netherlands have tried to use the explosions, which in just a fraction a second released more energy than the sun emits in 150,000 years, to learn about what neutron stars look like inside.
"This explosion was akin to hitting the neutron star with a gigantic hammer, causing it to ring like a bell," said Richard Rothschild, an astrophysicist at the University of California's Center for Astrophysics and Space Sciences and one of the authors of the journal report. "Now the question is, What does the frequency of the neutron star's oscillations - the tone produced by the ringing bell - mean?," he asked in a press release.
"Does it mean neutron stars are just a bunch of neutrons packed together? Or do neutron stars have exotic particles, like quarks, at their centers as many scientists believe? And how does the crust of a neutron star float on top of its superfluid core? This is a rare opportunity for astrophysicists to study the interior of a neutron star, because we finally have some data theoreticians can chew on. Hopefully, they'll be able to tell us what this all means."
Where did the hammer come from? The astrophysicists suspect, the release said, that "the burst of gamma-ray and X-ray radiation from this unusually large explosion could have come from a highly twisted magnetic field surrounding the neutron star that suddenly snapped, creating a titanic quake on the neutron star.
"The scenario was probably analogous to a twisted rubber band that finally broke and in the process released a tremendous amount of energy," said Rothschild. "With this energy release, the magnetic field surrounding the magnetar was presumably able to relax to a more stable configuration."
The research for published in the current issue of the Astrophysical Journal.

Image: Artist's conception of the December 27, 2004 gamma ray flare expanding from SGR 1806-20. Credit: NASA

Soul Searching

2005-07-12T06:44:00.000-04:00

Descartes is dead, long live Spinoza. Neuroscientists and philosophers have now firmly rejected Descartes's mind-body dualism, embracing instead his peer and rival Spinoza, who believed that the soul and the body are one. Using technologies like functional magnetic resonance imaging, or fMRI, they have been probing the brain, seeking neural firing patterns that correspond with awareness and the self. Problem is, fMRI is still fairly crude, making their research quite fuzzy.
But now a team of American and Japanese scientists have proposed a revolutionary method to explore the brain, threading the thinking organ with platinum nanowires 100 times thinner than a human hair. The wires, which would enter the brain through blood vessels like a catheter, "may one day allow doctors to monitor individual brain cells," the researchers said.
That's great news, since one day the method could let them see in clear detail what really happens in the brain and which neurons snap into action when we reflect on our lives and ourselves, when we think of our loved ones, or when we just crave a cup of strong coffee in the morning.
"In this case, we see the first-ever application of nanotechnology to understanding the brain at the neuron-to-neuron interaction level with a non-intrusive, biocompatible and biodegradable nano-probe," said Michael Roco, senior advisor for nanotechnology at the National Science Foundation, which funded the research
The researchers envision "an entire array of nanowires being connected to a catheter tube, which could then be guided through the circulatory system to the brain. Once there, the nanowires would spread into a kind of bouquet, branching out into tinier and tinier blood vessels until they reached specific locations. Each nanowire would then be used to record the electrical activity of a single nerve cells, or small groups of nerve cells."
They also said that the technique could "greatly improve doctors' ability to pinpoint damage from injury and stroke, localize the cause of seizures, and detect the presence of tumors and other brain abnormalities." Since the wires could deliver electrical impulses as well as receive them, the method has potential as a treatment for Parkinson's and similar diseases.
As for finding the neural expression of the soul, the researchers stayed mum. But say it works, it seems that the technique could provide much sought after answers about who we are and where the self and awareness come from.
The research was carried out by scientists from New York University, MIT, and the Univesity of Tokyo. It was published in the current issue of the Journal of Nanoparticle Research.

Photo credit: Rat neurons, Omegafilters

Big Science

2005-07-01T21:12:00.000-04:00

Looking for ways to celebrate the 125 years since Thomas Edison first published his
Science on July 3, 1880, the magazine's editors have decided to hail the demise of ignorance. Tracing the largest holes in our scientific knowledge, the editors published a list of 25 "big questions," which they think have the greatest chance of being answered over the next quarter of century.
Though boredom is a state rarely experienced by Astralavista readers, if you find your brain underutilized over the upcoming long weekend, try to tackle this sampling. Even better, come up with your own and post it here. Here we go:
* What is the universe made of? In the last few decades, cosmologists have discovered that the ordinary matter that makes up stars and galaxies is less than 5 percent of everything there is. What is the nature of the "dark" matter that makes up the rest?
* What is the biological basis of consciousness? In contrast to Rene Descartes' 17th-century declaration that the mind and body are entirely separate, a new view is that whatever happens in the mind arises from a process in the brain. But scientists are only just beginning to unravel those processes.
* Why do humans have so few genes? To biologists' great surprise, once the human genome was sequenced in the late 1990s, it became clear that we only have about 25,000 genes -- about the same numbers as the flowering plant Arabidopsis. The details of how those genes are regulated and expressed is a central question in biology.
* How much can human life span be extended? Studies of long-lived mice, worms and yeast have convinced some scientists that human aging can be slowed, perhaps allowing many of us to live beyond 100, but others think our life spans are more fixed.
* Will Malthus continue to be wrong? In 1798, Thomas Malthus argued that human population growth will inevitably be checked, for example by famine, war or disease. Two centuries later, the world's population has risen sixfold, without the large-scale collapses that Malthus had predicted. Can we continue to avoid catastrophe by shifting to more sustainable patterns of consumption and development?

Image: Artist's impression of the early universe, less than 1 billion years old. Courtesy of A. Schaller of the STScI

A Divine Touch

2005-06-30T21:45:00.000-04:00

A month ago, this blog had a piece on Steven Benner, biologist from the University of Florida, and one of the pioneers in the field of synthetic biology.
Benner is seeking to build in his university lab brand new life, or as he put it, "artificial biochemical systems that reproduce the complex behavior of living systems, including their genetics, inheritance, and evolution." He said:"The ultimate goal of a program in synthetic biology is to develop chemical systems capable of self-reproduction and Darwinian-like evolution."
Yet now it looks that Benner might be a little late from the gate.
Yesterday the Wall Street Journal ran a fascinating story about J. Craig Venter, the innovative biologist who tied the U.S. government in decoding the human genome in 2000.
Now Venter has launched a new company, called Synthetic Genomics Inc., whose goal is, he told the Journal, the creation of the first "human-made species." The company, which is funded by $30 million from "several weathly private investors," as well as, interestingly, a $12 million grant from the U.S. Department of Energy, will first attempt to create a "made-to-order" bacterium by assembling genes like pieces of software code into a "man-made genome [that] would be installed inside a bacterium whose own genes have been removed."
Venter says that such frankenstein bacteria could start new ways of industrial production of drugs, chemicals, and energy, like ethanol.
Venter believes, the Journal says, that by creating such lifeforms he "may come closer to understanding what life is and how scientists can manipulate it for the benefit of human kind."
Venter told the paper: "This is the step we have all been talking about. We're moving
from reading the genetic code to writing it."

Illustration by L.J. Lapre

Celestial Soiree

2005-06-23T22:40:00.000-04:00

Space Daily has a great little piece on the upcoming celestial conjuction of Venus, Mercury and Saturn.
Anybody with a telescope, or at least a good pair of binoculars, should get ready at sunset this weekend when the three planets will form a tight, bright triangle above horizon. Calling it "spectacular," the report higlights some cool trivia about the event. So clutter your head:

The closest planet to the sun, Mercury, is not the hottest. Venus is. The surface temperature of Venus is 870 F (740 K), hot enough to melt lead. The planet's thick carbon dioxide atmosphere traps solar heat, leading to a runaway greenhouse effect.

Venus is so bright because the planet's clouds are wonderful reflectors of sunlight. Unlike clouds on Earth, which are made of water, clouds on Venus are made of sulfuric acid. They float atop an atmosphere where the pressure reaches 90 times the air pressure on Earth. If you went to Venus, you'd be crushed, smothered, dissolved and melted--not necessarily in that order.

Mercury is only a little better. At noontime, the surface temperature reaches 800 F (700 K).

Radars on Earth have pinged Mercury and found icy reflections near the planet's pes. How can ice exist in such heat? NASA's MESSENGER spacecraft is en route to Mercury now to investigate.

Here's one way to trick an astronomer: Show them a picture of Mercury and ask what it is. Many will answer "the Moon," because the Moon and Mercury look so much alike. But Mercury has something that the Moon does not: long sinuous cliffs called "lobate scarps." Some researchers think Mercury's scarps are like wrinkles in a raisin, a sign of shrinkage.

If you look at Venus or Mercury through a telescope, you won't be impressed. Both are featureless, Venus because of its bland clouds, Mercury because it is small and far away. Saturn is different. Even a small telescope will show you Saturn's breathtaking rings.

Galileo Galilei discovered Saturn's rings almost 400 years ago, but he didn't understand what he saw. Saturn's rings are improbably thin. If you made a 1-meter-wide scale model of Saturn, the rings would be 10,000 times thinner than a razor blade. They're full of strange waves and spokes and grooves. And no one knows where they came from.

One school of thought holds that Saturn's rings are debris from the breakup of a tiny moon or asteroid only a few hundred million years ago.

As recently as the Age of Dinosaurs on Earth, Saturn might have been a naked planet - no rings! Tiny moons orbiting among the rings today appear to be stealing angular momentum, which, given time, could cause the rings to collapse.

That's one of many questions being investigated by NASA's Cassini spacecraft, which has been orbiting Saturn since 2004. Cassini is on a 4-year mission to study Saturn's moons (all 34 of them), rings and weather.

Farming Brain Cells

2005-06-15T22:22:00.000-04:00

Researchers at the University of Florida have grown for the first time brain cells in a dish.

Field of neurons, courtesy of Laval University

Their report published in the current issue of the Proceedings of the National Academy of Sciences says that the scientists suceeded in growing mouse neurons in a dish. The researchers said that the "cell culture method holds the promise of producing a limitless supply of a person's own brain cells to potentially heal disorders such as Parkinson's disease or epilepsy."
Said UF neuroscientist Bjorn Scheffler: "We can basically take these cells and freeze them until we need them. Then we thaw them, begin a cell-generating process, and produce a ton of new neurons."
To be sure, the scientist can't say whether the results will be amenable to human brain therapy. They pointed out however that "if the discovery can translate to human applications, it will enhance efforts aimed at finding ways to use large numbers of a person's own cells to restore damaged brain function, partially because the technique produces cells in far greater amounts than the body can on its own," the scientists wrote in a press release.
The release also quoted Dr. Eric Holland, a neurosurgeon at Memorial Sloan-Kettering Cancer Center in New York who specializes in the treatment of brain tumors, but who is not connected to the research. "As far as regenerating parts of the brain that have degenerated, such as in Parkinson's disease, Huntington's disease and others of that nature, the ability to regenerate the needed cell type and placing it in the correct spot would have major impact," said Holland. "In terms of tumors, it's known that stem-like cells have characteristics much like cancer cells. Knowing what makes these cells tick may help by furthering our knowledge of the biology of the tumor."

Question of Quasars

2005-06-10T21:47:00.000-04:00

Quasars are the true masters of the universe. For no object in the whole astral menagerie packs more power than they do.

They don't look like much in telescopes, but probe one closer and you'll see the most awesome object in the universe. Quasars, which were first discovered by radio astronomers in the 1950s and hence their name, Quasi-stellar Radio Sources, are an amalgam of everything the universe can offer. At the center, there's a gargantuan black hole, a billion times more massive then the sun. The black hole's maw sucks in gas and dust from a vast accretion disc and burps light, copious amount of radio waves, and jets of electromagnetic radiation. This celestial orgy is surrounded by a vast galaxy orbiting the black hole at a safe distance.
Quasars are quite old. They were around when the universe was just 850 million years old. It takes light 13 billion years to cover the distance between most quasars and us. Hence they appear in telescopes like faint dots, although they are ten trillion times more luminous than the Sun,.
Since these behemoths are so old, scientists have long wondered what happened to them and where are they today. Finally, they have some answers.
Scientists from the Virgo Consortium, a group of computational astrophysicists from European, American, Canadian and Japanese universities, have come up with the Milenium Run, a powerful computer simulation of the evolution of the universe, including the formation of galaxies and quasars. They say in a new paper published in the journal Nature that "by tracking the merging history trees of the host halos, we find that all our quasars candidates end up today as the central galaxies in rich clusters."
The Virgo Consortium says that its model also allows to "establish evolutionary links observed at different epochs” of the universe.
That's great news for proponents of the cold dark matter model (CMD), the leading theory of the evolution of the universe, observes Nickolay Gnedin, astrophysicist from the University of Colorado at Boulder. He reported in Nature that some scientists "naturally question" whether 850 million years after the Big Bang was long enough time for such gargantuan objects to form. They questioned the validity of the CMD, which describes how small, slowly moving particles of dark matter combine in larger structures in the universe, saying that the theory works too slowly and doesn't give quasars enough time to assemble.
The consortium's results put such fears to rest: "We demonstrate that galaxies with supermassive central black holes can plausibly form early enough in the standard cold dark matter cosmology to host the first known quasars, and that these end up at the centers of rich galaxy clusters today.

See You In Infinity

2005-06-07T00:13:00.000-04:00

John D. Barrow, a mathematics professor at the University of Cambridge, has written a playful book dealing with the consequences of infinity called The Infinite Book.

Barrow addresses and illustrates many of the mind-boggling and glorious possibilities of living in an infinite universe where everything that has a finite probability will happen merely by chance (without any supernatural meddling).
He uses the Shakespearean monkey paradox to flesh out his case. According to this paradox, a truly random and infinite universe will one day produce all the works of Shakespeare, as if created by a mob of monkeys hitting randomly the keys of a typewriter.
Barrow has ferreted out a web site simulating the simian effort called the Monkey Shakespeare Simulator. In the simulator, which launched in July 2003, time passes 86,400 times faster than real life and each monkey is assumed to press 1 typewriter key per second. In the beginning, there were 100 monkeys, and the increase in population is continuously updated. (The lifespan of a monkey is about 50 years.) As of today, the monkey record is a string of 25 keystrokes, which happen to match a line of text from Shakespeare's Romeo and Juliet. After 2.65157 times 10 to the 49th power of monkey years, a monkey typed: "Barnardo. Who's there?
bP,Rx:E7x[)C5enduo0hdGWQelPy:gI..."
So who's out there? If the universe is truly infinite, then all of us, doing everything we've ever dreamed of, and everything we've feared the most.

Let There Be Life

2005-06-02T22:17:00.000-04:00

Forget artificial intelligence. How about artificial life instead?

Steven Benner, a biologist from the University of Florida, is a man fundamentalists of many stripes aren't going to like. For if he's right, they'll have to close shop. Benner's one of the leaders in the field of synthetic biology. He's seeking to build artificial life, or as he puts it, "artificial biochemical systems that reproduce the complex behavior of living systems, including their genetics, inheritance, and evolution."
He's had some remarkable success. In February 2004, Benner reported in the Nucleic Acids Research journal that his team produced a system that "for the first time can mimic the natural evolutionary process living organisms undergo." Benner reported that his team "showed that an artificially created DNA-like molecule containing six gene-building nucleotides - instead of the four found in natural DNA - could support the molecular 'photocopying' operation known as polymerase chain reaction. The artificial DNA-like molecule directed the synthesis of copies of itself and then copies of the copies, mimicking the natural process of evolution as it was first outlined by Charles Darwin." (Of course, one of the evolutionary prerequisites is the ability of the evolving system to make mistakes, some of which might be beneficial. Benner's report did not address that issue.)
Here's a summary of Benner's work that will be coming down the pike:

"The ultimate goal of a program in synthetic biology is to develop chemical systems capable of self-reproduction and Darwinian-like evolution. Such systems will support a "bottom up" exploration of the chemistry behind life, telling us how catalysts and pathways work, how they are regulated, and how they contribute to overall function in natural systems. From a chemical perspective, this work will also show how chemical reactivity is distributed in "structure space", an understanding key to combinatorial chemistry and the origin of life. Work is ongoing to:

* Chemically synthesize a larger repertoire of artificial genetic components.
* Develop DNA polymerases that better handle artificial genetic systems.
* Incorporate artificial genetic systems into artificial evolution experiments.
* Develop quantitative models for chemical evolution in artificial environments.
* Generate artificial chemical systems capable of Darwinian evolution.
* Improve diagnostics, detection, and genotyping systems for practical application."

Clearly, Benner is a man to watch. Here's more details on the work of Benner Group.

Danse Macabre

2005-06-01T21:50:00.000-04:00

It looks like heaven is hell after all.

This whirl of dancing ghouls is a picture of Eta Carinae, a huge dying star some 10,000 light years away from the Earth. The image taken by NASA's infrared Spitzer Space Telescope shows the convulsing star ripping to shreds its mother, the Carina Nebula, which bore it some 3 million years ago. The star is one of the Milky Way's most massive star. It's so huge, some 100 times more massive than the Sun, that it can barely hold itself together. Yet it's also one of the galaxy's youngest stars. The Sun, for example, is 4.5 billion years old.
Over the last 200 years, the star has been expelling material into space. In 1837, it flared to hundreds of times its normal brightness and disgorged about two percent of its total mass, enough to form two Suns, astronomers from the University of Texas said. NASA said that Eta Carninae might die in a supernova blast within our lifetime.
But Eta Carninae has already spawned its progeny. Burts of powerful ultraviolet radiation and stellar winds triggered by the star's paroxyms ripped apart the surrounding gas and dust and "shocked" new stars into being, NASA said. "When massive stars like these are born, they rapidly begin to shred to pieces the very cloud that nurtured them, forcing gas and dust to clump together and collapse into new stars. The process continues to spread outward, triggering successive generations of fewer and fewer stars. Our own Sun may have grown up in a similar environment."
The agency explained that "the new Spitzer image offers astronomers a detailed 'family tree' of the Carina Nebula. At the top of the hierarchy are the grandparents, Eta Carinae and its siblings, and below them are the generations of progeny of different sizes and ages."
(The false colors in the Spitzer picture correspond to different infrared wavelength, NASA said. Red represents dust features and green shows hot gas. Embryonic stars are yellow or white and foreground stars are blue. Eta Carinae itself lies just off the top of image. It is too bright for infrared telescopes to observe.)

Shooting The Moon

2005-05-31T22:40:00.000-04:00

Messenger, the Mercury-bound spacecraft NASA launched last August to explore the solar system's first planet, has delivered an unexpected gift.

On May 11, it snapped a fascinating picture of the Earth and the Moon. The shot, taken from some 18.4 million miles away, is a wonderful exhibit of the huge distance between us and our rocky satellite. The image comes as a surprise, considering that a full moon hanging over the horizon often looks like you could hit it with a rock.
In this picture, the distance between the Moon and the Earth is some 400,000 kilometers (248,000 miles), putting the Moon near its apogee at 405,000 kilometers. Apogee is the maximum distance the moon can reach away from the Earth. (The minimum distance, called perigee, is 363,000 kilometers.)
Expect more shots to come. Messenger will keep snapping away, testing its instruments, until August, when it's due for a fly-by around the Earth. Our planet's gravity will sling it towards Venus and then on to Mercury, which it will keep studying until 2011.

Iron Age

2005-05-30T22:48:00.000-04:00

NASA says that most of the iron in ancient galaxies anchored by supremassive black holes have been forged when the universe was still young.

NASA's Chandra X-ray observatory studied spectra from 300 supermassive black holes in the centers of distant galaxies some 9 billion and 11 billion light years away. The peaks in the spectra produced by X-ray emission from iron atoms showed that approximately the same amount of iron was present in both sets of the holes. "This implies that most of the iron in the galaxies that contain these supermassive black holes was created before the Universe was about 2 billion years old, when galaxies were very young," NASA said. "The amount of iron around black holes has not changed significantly over the past 11 billion years."
The black hole in the center of our home galaxy holds a mass equal 4 million suns. It is estimated to be about 14 million miles (23 million kilometers) across, fitting within the orbit of Mercury around the sun. Since the Milky Way is estimated to be 13.6 billion years old, born just 200 million years after the "Dark Age" that succeeded the Big Bang, Chandra observartions may apply to our own iron. Something to think about when you next order spinach.

Life on Titan?

2005-05-25T21:18:00.000-04:00

Scientists from the University of Arizona operating the Cassini spacecraft have been able to get some stunning surface pictures of Saturn' s perpetually clouded moon Titan.

But they've been baffled by a mysterious orange-colored spot near the moon's equator.
Members of the Cassini team have guessed that the 300-mile wide area might be a wound from a recent asteroid strike, or that the orange bruise is a mixture of water ice and ammonia oozing out of an ice volcano.
If that's the case, the spot might be a great place to start looking for extraterrestrial life.
In many ways, Titan, the second largest moon in the solar system after Jupiter's Ganymede, resembles the Earth some four billion years ago. It's the only known moon with a fully developed, planet-like atmosphere rich in nitrogen and methane. Such chemical brew could support the assembly of long organic molecules, similar to those, which preceded early RNA and DNA.
However, for life to be possible the moon "would need liquid water, which is not stable for long because Titan is too cold," said the Cassini scientists. (Titan's surface temperature averages -289F (-178C).) But "many of the large icy moons in the outer solar system host active water volcanism. Most of them contain a lot of liquid water, which flows across their surfaces in the same way lava does on Earth. Their internal heat initiates a melt that rises to the surface. These moons also contain various substances that are antifreezes (e.g. ammonia or formaldehyde). They are mixed into the water which lowers the density of liquid water and helps the water come up to the surface through the more dense icy crust."
Titan can also be heated with large asteroid impacts. "In the early 1990s, Carl Sagan and W. Reid Thompson of Cornell University suggested that impacts on the surface of Titan would melt the icy crust and produce liquid water," said Jonathan Lunine, professor of planetary sciences at the University of Arizona. He and a Russian colleague have been modeling impacts on Titan "to see what fraction of the crater would become liquid due to an impact." The couple computed that "an impact of a one-kilometer-diameter comet can turn about 5 percent of a crater's interior into liquid." Their simulations show that "the areas potentially containing organic matter would not be heavily shocked in an impact. Organic material survives such events and would be tossed in the crater where the liquid water would exist. When life on Earth originated about 4 billion years ago, large impacts were frequent."

Trip To The Edge

2005-05-24T21:49:00.000-04:00

Voyager 1, our messenger to the cosmic emptiness that lifted off the Earth in 1977, has reached the edge of the solar neighborhood.

The spacecraft "entered the solar system's final frontier, a vast, turbulent expanse where the Sun's influence ends and the solar wind crashes into the thin gas between stars," NASA said today. Said Edward Stone, Voyager project scientist at the California Institute of Technology: "Voyager has entered the final lap on its race to the edge of interstestellar space."
MIT's John Richardson, the principal Investigator of the Voyager plasma science said that "the consensus of the team now is that Voyager 1, at 8.7 billion miles from the Sun, has at last entered the heliosheath, the region beyond the termination shock."
The termination shock, NASA explained, is "where the solar wind, a thin stream of electrically charged gas blowing continuously outward from the Sun, is slowed by pressure from gas between the stars. At the termination shock, the solar wind slows abruptly from its average speed of 300 to 700 km per second (700,000 - 1,500,000 miles per hour) and becomes denser and hotter."
Voyager 1 has an identical twin brother, Voyager 2. That craft was concieved as a back-up for Voyager 1, but actually lifted off a month earlier, are on different flight paths. Voyager 1 is traveling at a speed of 3.6 astral units per year. (Astral unit is the distance between the Earth and the Sun, or about 93 million miles.) Voyager 2 is about 6.5 billion miles away from the Earth and moving at about 3.3 AU per year.
NASA estimates that the spacecraft could remain functional until 2020.

This Is Radio Saturn

2005-05-23T21:12:00.000-04:00

NASA reported today that its Cassini spacecraft has obtained the most detailed look ever at Saturn's rings, including the B ring, which has eluded previous robotic explorers.

"All ring features appear to be populated by a broad range of particle sizes that extend to many meters in diameter at the upper end," said Dr. Essam Marouf, Cassini team member.
Marouf said in a NASA press release that "at the lower end, particles of about 5 centimeters (roughly 2 inches" seem to abundant in the outer rings.
NASA said that "the inner and outer parts of ring B contain rings that are hundreds of kilometers wide (hundreds of miles) and vary greatly in the amount of material they contain. A thick, 5,000-kilometer-wide (3,100-mile) core contains several bands with ring material that is nearly four times as dense as that of ring A and nearly 20 times as dense as that of ring C."
Cassini analyzed the rings by beaming radio signals through the rings to Earth. "Scientists then watch how the strength of the radio signal is affected as the signal passes through ring material," NASA said. "The denser a ring is, the weaker the signal received. The experiment helps scientists map the distribution of the amount of ring material and determine the ring particle sizes."
From edge-to-edge, the ring system is wider than the gap between Earth and the Moon. But the rings are only 30 meters thick, or 100 feet. This is the first of many such observations Cassini will be conducting over the summer.

Out of Time

2005-05-18T23:40:00.000-04:00

Here's one last take on the MIT time travel convention.

It's been proposed that nobody from our future showed up not because they didn't want to or because humans do not exist in the future, but because they simply couldn't. They were prevented by the many worlds interpretation of quantum mechanics.
Here's how. The MWI basically says that there's an infinitely large set of universes called a multiverse. At every instant, the universe splits off an infinity of other universes. Each of these universes has a copy of every quark, electron and gluon of the original universe, but is completely independent. In a multiverse, anything is possible and everything happens. For example, in one splinter universe you are writing this blog and I'm the reader.
But here's the catch. Two copies of the same particle cannot exist in the same universe without violating the laws of quantum mechanics. Therefore, when time travelers from our future arrived at the MIT campus two weeks ago, the universe immediately sprouted a new branch and re-routed the visitors away from us before we had a chance to debrief them.
The MWI, which was first proposed by English physicist Hugh Everett III in 1957, had some powerful backers like Stephen Hawking and John Archibald Wheeler.
However, they both changed their minds. "It required too much metaphysical baggage to carry around," Wheeler told physicist Heinz Pagels, author of the Cosmic Code. Hawking invoked his "chronology protection conjecture," which states that although quantum particles like photons can theoretically travel in time, "the laws of physics conspire to prevent time travel by macroscopic objects." The chief obstacle here is the second law of thermodynamics, which says that entropy, the measure of messiness of a system, must be growing with time for any closed system, including the universe. Reverse time's arrow and you'll most likely violate this bedrock of physics.
Perhaps the most eloquent rebuttal of the multiverse theory comes from Pagels himself: "But isn't this multi-reality and superspace all a great fanstasy, which although not strictly ruled out by quantum theory, is not required by it? You speak of all those other worlds as if they were real, when in fact, it is only this world - the one we live in - that we can ever know."

No Future?

2005-05-17T21:29:00.000-04:00

Here's an update on the MIT time travelers's bash.

It didn't go so well. "Unfortunately, we had no confirmed time travelers visit us," the organizers said. "We may be doing a run of t-shirts if there's enough interest."
That leaves us with a disconcerting question. Maybe no time travelers arrived from the future because there will be no future. Maybe something really bad happens before we learn to shake the shackles of spacetime.
Which forces us to take solace in John Titor, the only self-indentified time traveler from the future to be living on Earth right now. He claims that he came back from 2036, using a time machine built by General Electric. If he's right, rejoice and start saving up for your time-traveling retirement cruise. Here's how you do it. Buy some GE stock. Now!

Cracking The Case of The Missing Ice Cap

2005-05-16T21:34:00.000-04:00

American scientists say they have solved the mystery of a missing Martian icecap.

Mars, like Earth, has two icy polar caps. While the north pole appears to a fairly ordinary specimen, the south pole is a "strange animal," said Jeffrey Barnes, a professor of atmospheric sciences at Oregon State University. The southern ice cap is tiny compared to its nothern brother, about ten times smaller. It is made of carbon dioxide ice, the same stuff that street corner ice cream vendors use to cool their popsicles. That's normal since Martian atmosphere is rich in carbon dioxide.
What's unusual is that this dry ice is sequestered away from the planet's south pole. The pole itself is in the "cryptic region" which doesn't appear to have any ice at all. "No one has been able to figure out why there is this peculiar distribution of ice deposits," said Barnes.
Until now. Analyzing images and temperature measurements from the Mars Global Surveyor probe and plugging the data into climate models, Barnes and his colleagues from NASA figured out that the south pole is covered by a three-fee deep lid of crystal clear ice that's completely transparent. "We basically think the cryptic region is a sheet on incredibly clear ice," said Barnes. "The reason for the low reflectivity is that the ground beneath it shows right through it."
The scientists think that unlike visible ice caps, which on Mars as well as on Earth accumulate during snowfall, the clear ice forms when the Martian carbon dioxide atmosphere reaches brutal -193 F, starts behaving like freezing molasses, and "condenses right on the ground and forms slabs of ice."

Black Holes Keep Their Secrets

2005-05-12T21:52:00.000-04:00

There were no more details today from NASA on the powerful gamma ray burst reported yesterday. NASA scientists speculated that the burst was the result of a merger of two orbiting black holes or neutron stars and telegraphed the birth of a brand new black hole. However, Caltech physicist Kip Thorne has written extensively on the topic. A passage from his Black Holes and Time Warps gives an idea of what may have happened:
"The holes' inspiral [motion] is slow at first, but the closer the holes draw to each other, the faster they move, the more strongly they radiate their ripples of curvature [of spacetime], and the more rapidly they lose energy and spiral inward. Ultimately, when each hole is moving at nearly the speed of light, their horizons touch and merge. Where there were two holes, now there is one - a rapidly spinning dumbbell shaped hole. As the horizon spins, its dumbbell shape radiates ripples of curvature, and those ripples push back on the hole, gradually reducing its dumbbell protrusions until they are gone. The spinning hole's horizon is left perfectly smooth and circular in equatorial cross section...
"By examining the final, smooth black hole, one cannot in any way discover its past history. One cannot discern whether it was created by the coalescence of two smaller holes, or by the direct implosion of a star... The black hole has no 'hair' from which to decipher its history."
This account spells trouble for astronomers trying to decipher what happened on May 9. They will have to pore over old photographs of the cosmic region and look for traces of black holes or neutron stars. The new bald black hole won't give up any clues. One great source of evidence would be gravitational waves. Unfortunatelly, LIGO, Laser Interferometer Gravitational Wave Observatory, which still pretty much in debugging mode, has nothing to report.

NASA Craft Observes Black Hole Birth For The First Time

2005-05-11T21:16:00.000-04:00

Based on data coming out of NASA today, the agency's Swift gamma ray observatory has seen for the first time the birth of a black hole. The Swift registered a short and extremely powerful burst of gamma rays on May 9. NASA scientists speculate that the explosion was caused by a collision of two older low-mass black holes or two neutron stars.
Gamma bursts are the most violent events in the universe. NASA said that the burst, numbered grb050509b, "appears to have occurred near a galaxy that has old stars and is relatively nearby, about 2.7 billion light years away from Earth. This is consistent with the theory that short bursts come from older, evolved neutron stars and black holes. In contrast, longer gamma-ray bursts tend to be in young, distant galaxies filled with young, massive stars, remnants of the early universe."
"We are combing the region around the burst with the Keck Telescope in Hawaii for clues about this burst or its host galaxy," said Shri Kulkarni, a gamma-ray burst expert from the California Institute of Technology.
The system's image comes from Joshua Bloom, gamma-ray researcher at the University of California, Berkeley.

Beyond Orion

2005-05-10T21:56:00.000-04:00

The Orion Nebula, a dazzling cloud of stellar dust riddled with bullet holes of bright young stars some 1,500 light years away, may be the most rewarding sight for any a backyard astronomer. Yet beyond the beauty, there lays a secret. It turns out that nebula holds important clues about the formation of our solar system.
NASA's Chandra X-ray observatory just snapped pictures of 1,400 stars in the nebula, including 30 which resemble the early sun. The photos revealed that some of Orion's youngest stars, just 10 million years old, erupt regularly in huge stellar flares, which dwarf in size, frequency and energy any such electromagnetic burps expelled by our Sun.
But that may not have always been the case. NASA astronomers analyzing the pictures say that the Sun may have also pumped out powerful flares when it was still young and boisterous, some 4.6 billion years ago. If that's the case, such outbursts have probably shaped planetary distribution of our solar system. "Big X-ray flares could lead to planetary systems like ours, where Earth is a safe distance from the sun," said Eric Feigelson of Penn State University. "Stars with smaller flares, on the other hand, might end up with Earth-like planets plummeting into the star."
Feigelson and his colleagues said that violent X-ray flares can create turbulence when they strike planet-forming disk, blow away nascent planets like soap bubbles, and prevent planets from burning up inside young stars. "Although these flares may be creating havoc in the disks, they ultimately could do more good than harm," said Feigelson. "These flares may be acting like a planetary protection program."
NASA wrote in a press release that "about half of the young suns in Orion show evidence of planet-forming disks including four lying at the center of proplyds (proto-planetary disks) imaged by NASA's Hubble Space Telescope."

Sticky Glitter

2005-05-09T21:23:00.000-04:00

Researchers at the the Georgia Institute of Technology and the University of California at San Francisco can spot tumors by tagging cancer cells with tiny gold nuggets. The scientists have engineered gold nanoparticles that are strongly attracted to the "epidermal growth factor receptor," a protein that sticks out of the surface of many cancer cells. The scientists chose gold since it's extremely efficient at absorbing and scattering light, making tumors glow like cities at night. "You can tell with a simple microscope that the whole cancer cell is shining," said Mostafa El-Sayed, director of the Laser Dynamics Laboratory and chemistry professor at Georgia Tech. "The healthy cell doesn't bind to the nanoparticles specifically, so you don't see where the cells are. With this technique, if you see a well defined cell glowing, that's cancer."
El-Sayed and his team reported that "the gold nanoparticles have 600 percent greater affinity for cancer cells than for noncancerous cells." They tested the technique using cell cultures of two different types of oral cancer and one nonmalignant cell line.
El-Sayed said that the new method is not toxic to humans and allows doctors make fast and detailed cancer observations with just a basic lab microscope. "If you take cells from a cancer stricken tissue and spray them with these gold nanoparticles that have this antibody you can see the results immediately. The scattering is so strong that you can detect a single particle," said El-Sayed.
This is not the first time researchers used gold to blow cancer's cover. Two years ago esearchers at Northwestern University developed gold marking and detection systems for breast and prostate cancer as well as many other types of cancer.

Save the Comet

2005-05-08T10:04:00.000-04:00

Russian astrologer Marina Bai is suing NASA over its Deep Impact mission designed to drive a spacecraft inside the Comet 9P/Tempel 1 on July 4. Bai, who's asking for $300 million, says that impact will disrupt the "natural balance of the Universe."
More strangely, a Moscow court actually took up the case.
A hearing was scheduled for May 6. So far now news on how it went.
The Deep Impact probe will crash a 39-inch spacecraft hauling some 700 pounds of copper into the 4-mile wide Tempel 1. The space craft will swoop down at a speed of 6.3 miles per second. The cosmic crash will take place 83 million miles away from Earth. NASA said that "the crater produced by the impact could range in size from the width of a large house up to the size of a football stadium and from 2 to 14 stories deep. Ice and dust debris will be ejected from the crater, revealing the material beneath."
The guts of comets are made of ice, gas and dust left over from the formation of the solar system 4.5 billion years ago and stored in a cosmic freezer beyond th orbit of Pluto. They hold important evidence about the birth and growth of Earth and other planets.

Time Travel at MIT

2005-05-05T22:38:00.000-04:00

Military insignia of a purported American time traveler John Titor

MIT is holding "the first and only" Time Traveler Convention this Saturday, May 7. (That's right, one is all you need since you can always come back.)
Leaving nothing to chance, the entirely serious event gives precise directions for all those arriving from the future, or the past: East Campus Courtyard, MIT, 42:21:36.025 N, 71:05:16.332 W.
All time travelers are required to bring "some sort of proof that you do indeed come from the future, and haven't just dressed like you do. We welcome any sort of proof, but things like a cure for AIDS or cancer, a solution for global poverty, or a cold fusion reactor would be particularly convincing as well as greatly appreciated."
The organizers admit that they not at all sure whether time travel is at all possible. However, they are quick to ad that " the ancient Greeks would have thought computers were impossible, and the Phoenicians certainly wouldn't have believed that humans would one day send a spacecraft to the moon and back. We cannot predict the future of science or technology, so we can only make an effort and see if any time travelers come to our convention."
Sadly, only astralavista readers with time machines can take advantage of this post, tunnel back and sign up. MIT has already shut down registration "due to the overwhelming response."

The Butterfly Effect

2005-05-04T22:02:00.000-04:00

Czech and American scientists have discovered the navigation gear that steers monarch butterflies on their annual pilgrimage from the north of the United States to Mexico. It's been known that the miniscule machinery resides in the monarch brain and guides the insect by analyzing the angle of polarized ultraviolet sunlight. But the researchers found that the key to the system is a link between the insect's eye and the brain region that holds the circadian clock circuits. The link, which the scientists spied by using tracer molecules illuminating circadian neural fibers connected to polarization photoreceptors in the eye, allows the butterflies compensate its position and flight path for the time of day. "This pathway has not been described in any other insect, and it may be a hallmark feature of butterflies that use a time-compensated sun compass," the researchers wrote. Since the link also supplies the brain with information about daylight, the scientists speculate that it might launch the monarchs's autumn migration. "The decreasing length of the day in the fall appears to be an important determinant for stimulating migratory behavior in butterflies," they said.
Of course, they went on to test their discovery and placed UV interference filters over the polarized light source simulating the sun in the lab. Sure enough, the poor monarchs got lost.

This Tobacco Is Good For You

2005-05-03T21:50:00.000-04:00

Scientists at Jefferson Medical College in Philadelphia have grown tobacco plants producing cancer fighting chemicals called monoclonal antibodies, which latch onto tumors and kill them like heat-seeking missiles. They are hoping that tobacco plants may soon become "antibody factories" producing proteins pounding variety of cancers.
The vegetal medicine seems to work. Results from animal trials show that the harvested antibodies attacked human colorectal tumors grown on mice and halted their growth. "The antibody produced in tobacco is as good as the antibody produced in animal cells," said Hilary Koprowski, professor of microbiology and immunology at Jefferson. She said that tobacco-derived antibody should be safer and less expensive to produce than antibodies currently grown in mice. The school says it is now looking for industry partners to begin mass production.
This is not the first time Jefferson scientists used tobacco to grow medicine. In the past they harvested rabies-fighting antibodies, which stopped the disease in infected mice.
Koprowski is already moving ahead with more research, testing new kinds of tobacco-grown antigens on breast and lung tumor cells.

Pretty Pictures

2005-05-02T22:53:00.000-04:00

The 15-year old Hubble Space Telescope, the workhorse space camera that snapped 700,000 pictures of the farthest and most violent corners of the universe, is dying. If nothing is done, its batteries and altitude control gyroscopes are going to fail within the next two or three years, leaving it crippled and unable to do any research.
Today there's little hope for a fix. The Bush White House seems to be ready to pull the plug on the Hubble, saying it wants to go to Mars instead. NASA says that servicing the Hubble from the the International Space Station would be too dangerous.
No wonder that the Space Telescope Science Institute in Baltimore, Maryland, which runs the telescope is appealing for clemency directly to the public. Doing what it does best, it released some stunning images of the universe. Take a look. The cosmos is frightening and awesome. Somehow, we also fit in.

It's Getting Hot In Here

2005-05-01T21:49:00.000-04:00

A new study published by NASA, Columbia University and the Lawrence Berkeley National Laboratory says that Earth's energy is "out of balance," pointing out that the "energy imbalance is large by standards of the planet's history." The report said that more heat is being absorbed from the Sun than is emitted back to space, causing global warming.
Though hardly surprising, the finding is quite juicy, given that the study was partly funded by American tax dollars and published by a U.S. government agency. The Bush administration has steadfastly dismissed global warming as greenie hubris and refused to join the Kyoto protocol drafted to cut emissions of greenhouse gasses.
The scientists led by NASA's Jim Hansen gathered 10 years of climatic records from satellites and buoys, and used computer models to study the Earth's oceans. "The energy imbalance is an expected consequence of increasing atmospheric pollution, especially carbon dioxide, methane, ozone, and black carbon particles," said Hansen. "These pollutants block the Earth's heat radiation from escaping to space, and they increase absorption of sunlight."
The scientists wrote that the imbalance between absorbed and radiateed heat is 0.85 watts per meter squared. "That will cause an additional warming of 0.6 degrees Celsius (1 degree Fahrenheit) by the end of this century," they said. "To understand the difference, think of a one-watt light bulb shining over an area of one square meter (10.76 square feet). Although it doesn't seem like much, adding up the number of feet around the world creates a big effect. To put this number into perspective, an imbalance of one-watt per square meter, maintained for the past 10,000 years is enough to melt ice equivalent to one kilometer (.6 mile) of sea level, if there were that much ice."

Planet Ho!

2005-04-30T11:22:00.000-04:00

Astronomers from the European Southern Observatory settled today a year long dispute whether a big red orb five times the mass of Jupiter and orbiting a young brown dwarf star is indeed a planet. "I'm more than 99 percent confident" that the object is a planet, said Benjamin Zuckerman, UCLA professor of physics and astronomy and member of NASA's Astrobiology Institute. "The two objects are moving together; we have observed them for a year, and the new images essentially confirm our 2004 finding."
This is the first time astronomers have photographed a planet outside out solar system. Although more than 150 such extra-solar planets have been found, they were detected by measuring the wobble or the changes in luminosity of their anchor stars.
The scientists also sketched out a rough chemical make-up of the planet. They said that the spectrum of the radiation leaving the planet "presents a strong signature of water molecules, thereby confirming that it must be cold." Said Anne-Marie Lagrange of the Grenoble Observatory in France: "Our discovery represents a first step towards one of the most important goals of modern astrophysics: to characterize the physical structure and chemical composition of giant and, eventually, terrestrial-like planets.
ESO astronomer Gael Chauvin said that the giant planet "most probably did not form like the planets in our solar system. Instead it must have formed the same way our Sun formed, by a one-step gravitational collapse of a cloud of gas and dust."
The distance between the planet, labeled 2M1207b, and the brown dwarf, numbered 2M1207A, is 55 times larger than the radius of Earth's orbit around the Sun. The planet is near the southern constellation of Hydra and approximately 200 light years from Earth. It was first photographed last April.

Cosmic Cannibal

2005-04-28T23:21:00.000-04:00

Harvard astronomers using NASA's Chandra X-ray Observatory have snapped a stunning picture of a tiny dwarf star cannibalizing its giant neighbor.
The stars, called Mira A and B, are about 6.5 million miles apart (circa 1.5 light years), as far as the Sun and Pluto. They are 420 lights years away from us in the constellation Cetus (Whale).
The stars are connected by a bridge of burning matter. The small and dense Mira B is pulling off and gorging on gas from the huge and bloated Mira A, and burping bursts of X-rays as it feasts.
Or so people thought. The new images also reveal unexpected X-ray radiation from Mira A. The astronomers said that the "internal turmoil" in the bloated Mira A could "create magnetic disturbances in the upper atmosphere of the star and lead to the observed X-ray outbursts, as well as the rapid loss of material from the star in a blustery, strong, stellar wind. Some of the material in the wind from Mira A is captured in an accretion disk around Mira B, where collisions between rapidly moving particles produce X-rays."
Said Margarita Karovska of the Harvard-Smithsonian Center for Astrophysics:
"Before this observation it was assumed that all the X-rays came from a hot disk surrounding a white dwarf, so the detection of an X-ray outburst from the giant star came as a surprise."
Mira A, whose diameter is 600 times larger than the Sun, is a red giant, an aging star whose nuclear fuel of hydrogen and helium will soon burn out. Renaissance astronomers named the star Mira, which means "Wonderful" in Latin, since it would dim and brighten every 331 days. The blinking is caused by the much smaller Mira B passing in front of it. Mira B is thought to be a white dwarf star about the size of the Earth.

High Resolution

2005-04-27T22:37:00.000-04:00

Astronomers at the European Space Agency have spotted features as small as a football field on stars as far as 2,000 light years, something that's never been done.
Using the XMM-Newton X-ray telescope, the scientists have observed thousands of burnings flecks spread over stellar surfaces and ranging from 300 to 3,000 feet in diameter on three neutron stars 500, 800, and 2000 light years away from us.
ESA said that the stellar pimples are most probably linked to magnetic field phenomena similar to earthly Polar lights. "This is where the star's magnetic field funnels charged particles back towards the surface, in a way somehow similar to the Northern light, or aurorae, seen at the poles of planets which have magnetic fields, such as Earth, Jupiter and Saturn," the scientists said.
Neutron stars are the fast-spinning, superdense cores that remain after supernova explosions. They are made almost entirely of neutrons and about as massive as the Sun. But their circumference is thousands times smaller, just 30 to 600 miles. Say, a Lego cube made of neutron star material with sides 1 centimeter long (2/5ths of an inch)would weigh as much as 340-meter cube of steel. Working like massive dynamos, they generate extreme magnetic fields.

Blood Dust

2005-04-24T22:16:00.000-04:00

Researchers at Washington University is St. Louis have developed blood-borne nanoparticles that can be loaded with a wide variety of drugs and directed to growing tumors.
The particles, each made of 100,000 molecules of undisclosed metal, carry an imaging agent that can be picked up by a MRI scanner and let doctors determine whether the drug reached its target. "When drug-bearing nanoparticles also contain an imaging agent, you can get a visible signal that allows you to measure how much medication got to the tumor," Gregory Lanza, associate professor of medicine. "You would know the same day you treated the patient and if the drug was at a therapeutic level." Since such imaging technology would disclose whether a drug therapy is working, it could dramatically lower doses typically used in chemotherapy, making the procedure potentially much safer.
The particles enter milimeter-sized, rapidly growing tumors by penetrating tiny new blood vessels, which feed them. To get the particles to bind to tumors, the researchers equipped them with tiny "hooks" that link only to complementary "loops" found on cells in newly forming blood vessels. When the nanoparticles hooked the "loops" on the new vessels' cells, they revealed the location of the tumors.
(For more on nano-MRI see Pumping Iron, March 20, and In Dust They Trust, March 17.)

Burning Blob

2005-04-22T22:49:00.000-04:00

Astronomers at the European Southern Observatory have snapped new images of the Blob, a sinister-looking reddish cloud of ionized gas in the Milky Way's cosmic sidekick, the Large Magellanic Cloud. The Blob looks like a cracked reptilian egg stretching some four light-years across. It's lit from withing by a powerfull object 200,000 times more luminous that the Sun. The astronomers speculate that the light source might be a very massive star of some 100 stellar masses in the process of being born.
"It is possible that the blob resulted from massive star formation following the collapse of a thin shell of neutral matter," said ESO astronomer Mohammad Heydari-Malayeri. Added his colleague Frederic Meynadier: "The formation mechanisms of these objects are not yet fully understood." Meynadier said that so far only a dozen of such "blobs" have been discovered.

Chock Full of Chondrules

2005-04-21T22:16:00.000-04:00

Scientists at the Lawrence Livermore National laboratory studying an ancient meteorite say they have determined the age of the solar system. By their counting, our cosmic neighborhood started condensing from a cloud of interstellar dust and gas between 4.567 billion and 4.565 billion years ago.
The scientists made the discovery by studying chondrules, milimeter-sized spheres thought to be among the first solids to have formed in the solar nebula, and "calcium aluminum inclusions" called CAIs.
Chondrules and CAIs have never been found in any terrestrial rocks, but they are often embedded in space rocks like the massive Allende meteorite, which crashed in Mexico in 1969 and scattered tons of debris over 100 square miles.
Both chondrules and CAIs contain strange isotopic signatures that pointed to their birth before the solar system formed. The assumption was that these tiny objects were probably the product of a nearby supernova.
The Livermore scientists working hand in had with researchers in Hawaii, Tokyo, the Smithsonian and MIT dated the oxygen 16 isotope present in Allende's chondrules and CAIs to crack the riddle. They discovered that the CAIs and chondrules were born about two million year apart, but tens of millions of years before any planets in the solar systems. Earth and the rest of the solar rocks are thought to have formed about 4.5 billion years ago.
"Over this span of about two million years, the oxygen in the solar nebula changed substantially in its isotopic makeup," said Livermore's Ian Hutcheon. "In the past the age difference between CAIs and chondrules was not well-defined. Refining the lifetime of the solar nebula is quite significant in terms of understanding how our solar system formed."

Little Green Men Redux

2005-04-20T21:59:00.000-04:00

They're green, they're little, they may have lived on Mars, but men they ain't. Scientists from the University of Colorado at Boulder have found a strange bunch of green microbes living inside acid-infused simmering rocks at the Yellowstone National Park. The researchers said that the discovery could be a boon for astrobiologist searching for life on Mars.
"This is the first description of these microbial communities, which may be a good diagnostic indicator of past life on Mars because of their potential for fossil preservation," said team member Jeffrey Walker. "The prevalence of this type of microbial life in Yellowstone means that Martian rocks associated with former hydrothermal systems may be the best hope for finding evidence of past life there."
Walker's colleague Norman Pace said that "the pores in the rocks where these creatures live have a pH value of one, which dissolves nails. This is another example that life can be robust in an environment most humans view as inhospitable."

Liquid Universe

2005-04-19T22:22:00.000-04:00

There's more news today coming out of Brookhaven about their big bang experiment. Danish physicists from the Niels Bohr Institute at the University of Copenhagen who took part in the research said that when the universe was just one microsecond old it behaved like a perfect liquid.
Until recently, researchers have thought that the quarks and gluons that appeared right after the big bang formed a gas. "The latest results from RHIC, however, indicate that under the extreme conditions just around the phase transition from quarks and gluons to ordinary matter, the quarks and gluons behaved as a liquid, in fact an almost perfect liquid," the reserachers said in a press release.
The scientist said that the liquid, burning at 1,000 billion degress Kelvin seemed to move "in a pattern that exhibits a high degree of coordination among the particles -- somewhat like a school of fish that responds as one entity while moving through a changing environment."

Big Bang Brew

2005-04-18T21:20:00.000-04:00

Researchers at the Relativistic Heavy Ion Collider in Brookhaven, NY have distilled a close cousin of quark-qluon plasma, the cosmic cocktail that existed just millionth of a second after the Big Bang.
The Brookhaven brew made by smashing gold nuclei accelerated close to the speed of light could tell us what the universe was like during the big bang, as well as provide experimental verifications of some of the arcane predictions made by string theory, which seeks to unify the laws of relativity and quantum physics. "We know that we've reached the temperature up to 150,000 times hotter than the center of the sun and energy density predicted to be necessary for forming such a plasma," said Sam Aronson, Brookhaven's Associate Laboratory Director for High Energy and Nuclear Physics.
Such temperatures should be hot enough to melt the very vacuum of space like ice and create unattached free quarks and gluons seemingly out of nothing, the researchers said.
Quarks and gluons are the basic building blocks of atomic nuclei. They make protons, neutrons and a host of other more exotic particles.

Diamond Bust

2005-04-15T22:24:00.000-04:00

It may be a good time to pawn your "rocks." A diamond star discovered last year hovers in the southern skies (see Bling, Bling Star). Now American scientists are saying that some of the 154 extrasolar planets found over the last decade could be also made of diamond. They said that such planets could be located even around stars like our Sun.
Marc Kuchner of Princeton University and Sara Seager of the Carnegie Institution in Washington said in a brand new paper that there could be low-mass extrasolar planets - smaller than 60 times the Earth's mass - rich in silicon carbide and other carbon compounds. "Although graphite should emerge as a surface layer in a differentiated carbon planet, a few kilometers into the planet's interior... pure carbon in a cool carbon planet should turn to diamond."
Kuchner and Seager got the idea to look for carbon planets from recent research done on the birth of Jupiter. Data suggested that Jupiter formed in a carbon-rich part of the primordial solar nebula and that Jupiter's embryo was a carbon planet. "If Jupiter could have formed from a carbon-rich embryo, we would expect that carbon-rich embryos should be relatively common and occassionaly observable as planets," they wrote.

Bling, Bling Star

2005-04-14T22:43:00.000-04:00

There are many spectacular sights in the universe, but a giant diamond suspended in the southern skies outshines them all. The cosmic gem known as BPM 37093 is actually a white dwarf. Such stars are the hot cores of stars like our sun left over after they use up their nuclear fuel and die. This particular white dwarf is made mostly of crystalized carbon, i.e. diamond, draped with a thin gasseous veil of hydrogen and helium.
The diamond star is located in the constellation Centaurus just short 50 light years away. It is 2,500 miles across and weighs 5 million trillion trillion pounds, which translates to approximately 10 billion trillion trillion carats.
"It's the mother of all diamonds!" said astronomer Travis Metcalfe from Harvard-Smithsonian Center for Astrophysics who led the team that made the discovery. "Some people refer to it as 'Lucy' in a tribute to the Beatles song 'Lucy In The Sky With Diamonds.'"
Team member Michael Montgomery from the Univresity of Cambridge said that "the hunt for the crystal core of this white dwarf has been like the search for the Lost Dutchman's Mine. It was thought to exist for decades, but only now has it been located."The team also said that the star rings like a "gigantic gong", undergoing constant pulsations.
Metcalfe said the team made the discovery by "measuring those pulsations, we were able to study the hidden interior of the white dwarf, just like seismograph measurements of earthquakes allow geologists to study the interior of the Earth. We figured out that the carbon interior of this white dwarf has solidified to form the galaxy's largest diamond."
The scientists wrote that our Sun will become a white dwarf when it dies 5 billion years from now. Some two billion years after that, the Sun's ember core will crystallize as well, leaving a giant diamond in the center of our solar system.
Although Lucy has been found a year ago, it's can be best viewed right now if you and your telescope happen to be in the southern hemisphere. The window on Lucy will close in June for another ten months.

Burning Horizons and Missing Holes

2005-04-13T22:22:00.000-04:00

Black holes have lost some of their enigma at the Physics 2005 conference held this week at the Institute of Physics in Warwick, England. First, Astrophysics professor Andrew Hamilton from the University of Colorado showed that space travelers getting close to the event horizon of a big black hole would be fried to death, rather than torn to pieces. Since gravity at an event horizon is proportional to the mass of a black hole divided by the horizon's area, the bigger the horizon the weaker its gravitational pull. In theory, it would be possible to travel near the surface of a gigantic black hole the size of billions of suns and fly safely back.
Not so, says Hamilton. He says that the core of any black hole is filled with hot, dense plasma slowly sinking into the infinitely dense and infinitely tiny singularity at its center. Anybody approaching the horizon would be incinerated by the plasma before he would have time to take off and write home.
Astronomer Royal Martin Reese and his group later reported that the huge black holes located in the centers of galaxies have been formed by mergers of small black holes rather than by gobbling up galactic material. In a twist, Reese's Cambridge colleague Martin Haehnelt said that a proof for this theory would be finding a galaxy with its central black hole missing. He explained that a black hole merger begins with two holes going into orbit around each other and spiralling ever closer together. In the cataclysmic blast of energy when they finally merge, any asymmetry can send the resulting black hole flying off into space. Said Martin Haehnelt: "If this happened we might find the occasional galaxy with its central supermassive black hole missing."

Look Up!

2005-04-12T21:48:00.000-04:00

Aping America's color-coded terror warnings, astronomers at MIT have overhauled the Torino Scale used to measure the likelihood of Earth's doomsday collision with comets and asteroids. The new chart has a colored scale from zero to ten. It goes from harmless white to blazing chimney red for the "certain global catastrophe" warning.
Perhaps most interesting is Level 8, the first of the chart's three red alerts. It will be called when "a collision is certain, capable of causing localized destruction for an impact over land or possibly a tsunami if close offsore. Such events occur on average between once per 50 years and oncer per several 1000 years," the chart says.
Uh oh. The Tunguska meteorite, a likely Level 8 event, exploded above the Taiga in 1908, nearly a century ago. It felled an estimated 60 million trees over 2,150 square kilometres but did not leave a crater. The impact was felt as far away as 1,000 kilometres. At 500 kilometres, witnesses had claimed to have heard a deafening bang and to have seen a cloud on the horizon. The power of the blast was estimated between 10 and 15 megatons of TNT, about the size of the Hiroshima bomb.
The scientists aren't worried. They said that the highest Torino level ever given to an asteroid was a four (yellow) last December, with a 2 percent chance of hitting Earth in 2029. After extended tracking of the asteroid's orbit, it was reclassified to level zero.

Cerebral Suicides

2005-04-11T22:04:00.000-04:00

Scientists at MIT have found a protein that stops neurons from committing apoptosis, or programmed cell suicide. They hope that braking brain cell death will help them rejuvenate damaged and diseased brain tissue in adults. The protein, called CPG 15, may also let them grow neurons outside the body and replace dead brain cells like broken screws.
The scientists said that neurons are commonly killed off during the early brain development when brain cell rapidly proliferate. But they pointed out that little is known how apoptosis works in the adult brain. Elly Nedivi, professor of brain and cognitive sciences at MIT, said that the protein can "drastically affect the final size and shape of the cortex." He said that extra CPG 15 gives rats bigger brains with "grooves and furrows like evolved mammalian brains with larger surface area." Now if only size equalled smarts.

Killer Application

2005-04-10T23:21:00.000-04:00

Neurosurgeons at Ohio State University have designed a killer virus that can slay brain tumor cells. The virus is a genetically altered herpes simplex virus that infects and reproduces only in malignant glioma cells and kills them, leaving other cells and tissues unharmed.
Malignant gliomas are fatal, progressive cancers in the brain. The average survival following diagnosis is about a year, said E. Antonio Chiocca, professor and chairman of neurological surgery at The Ohio State University Medical Center. They are usually treated using surgery, chemotherapy and radiation.
Chiocca engineered the killer virus to attack only cells that make a protein called nestin. The protein is produced by malignant glioma.
The researchers tested the virus in mice with implanted human gliomas. In one set of experiments, the researchers gave the virus to the mice early, seven days after implanting the tumors. Untreated mice lived for 21 days after tumor implantation. Eight of 10 mice treated with the virus survived 90 days after implantation. Two of 10 mice treated with a control virus survived 90 days.
Using the virus as a viable cancer therapy is still years away, though. "This is a preliminary study," said Chiocca. "This virus cannot yet be used in humans. To go from animal studies to human studies is a very long process, especially for a treatment that uses viruses."
This is not the first time neurosurgeons used the herpes virus to treat cancer. In 1992, Kenneth Culver, an oncology researcher at the National Cancer Institute, injected a modified retrovirus carrying a gene from the herpes virus directly into the brain tumors of mice and later humans. Soon, the tumors started expressing the herpes gene. Matt Ridley writes in Genome that "by then the cunning Dr. Culver was treating the patient with drugs for herpes and the drugs attacked the tumors. It seemed to work on the first patient, but on four of the next five it failed."

Stardust To Stardust

2005-04-08T21:57:00.000-04:00

Astrophysicists at the University of Manchester studying a distant nova have found clues on how such exploding stars helped to create the elements we and our planet are made of.
The scientists were using a giant radio telescope in the New Mexico desert to study the so-called Sakurai's Object located in the Sagittarius constellation. It is the only dying star that has been seen to blast back to life in modern times.
Albert Zijlstra, astrophysics professor at Manchester, said that the exploding star disgorged a large amount of carbon gas and dust into space. "These will find their way into regions of space where new stars form, and the dust grains may become incorporated in new planets." he said. "Our results suggest this source for cosmic carbon may be far more important than previously suspected." Zijlstra said that as much as 5% of the carbon on Earth may have come from similar stellar explosions.
Most of the other elements are created during much bigger, cataclysmic events called supernovas. The cores of such stars collapse to form so-called white dwarfs, neutron stars, or black holes.
The majority of stars cool down and die when they have used up most of their hydrogen fuel by converting it into helium. For the Sun, this will happen in about 4.5 billion years. [Before that, the sun will become a red giant, 100 times larger and 2,000 times more luminous, expanding near Mars's orbit and incinerating Earth as it grows.]
But some 25% of stars will experience a brief rebirth when their helium suddenly ignites and starts fusing into carbon. After the explosive re-ignition, the star will expand to giant proportions - expelling tonnes of carbon in the process - before rapidly burning out again. Zijlstra expects that the Sakurai's Object will cool down and die sometime after 2200.

Headless Flies Take "Mindful Flight"

2005-04-07T22:05:00.000-04:00

Scientists at Yale University have learned to remotely control fruit flies with laser pulses by genetically rigging their brains. They even made headless flies fly!
The researchers said that the laser made the flies jump, beat their wings and fly in an escape response. They also used laser light to activate the flies' dopamine neurons that stimulated walking and affected the types of paths the flies chose to follow.
"The ability to control brain functions non-invasively opens many new possibilities for the analysis of neural circuits, the search for the cellular substrates of behavior, and, possibly even restoring function after injury or disease,"
said Gero Miesenbock, associate professor of cell biology at Yale. "This is a significant step toward moving neuroscience to active and predictive manipulation of behavior."
Mind control? Not really. The researchers showed "that even headless flies take mindful flight if the correct set of neurons is photo-activated." Sighs one New York City boss: "If only laser like that worked on people, I'd have an easier job managing!"

Monkey Business

2005-04-06T18:28:00.000-04:00

American scientists have found a chunk of human chromosome that may have caused the split of hominids from chimpanzees and launched the emergence of the human race five million years ago.
LaDeana Hillier of the Genome Sequencing Center at Washington University School of Medicine in St. Louis said she and her colleagues found on human chromosome 2 what "we think may be remnant of the centromere of one of the two chimp chromosomes that merged to form the human chromosome 2."
A centromere is the "cinched" part of the chromosome where the where the chromatids, the chromosome's two rods, are held together to form an X shape.
Human chromosome 2, the second largest human chromosome, was formed by the merger of two chimpanzee chromosomes recently renamed chimp chromosomes 2a and 2b.
Matt Ridley wrote in his book Genome that such chromosome fusion may have taken place after a small group of chimps got isolated in northern Africa by a cataclysmic flood some five million years ago. Ridley said that when the primates were "becoming inbred, flirting with extinction, exposed to the forces of the genetic founder effect (by which small population can have large genetic changes thanks to chance), this little band of apes shares a large mutation: two of their chromosomes have become fused. Henceforth they can breed only with their own kind, even when the 'island' rejoins the mainland." The rest, he says, is history.

Cannibal Galaxy

2005-04-05T22:38:00.000-04:00

The Hubble telescope has snapped a fascinating picture of a cannibal galaxy suffering from a bout of indigestion after it devoured a number of smaller peers. The galaxy called NGC 1316 is in the Fornax galaxy cluster 75 million light years away.
"The inner regions of the galaxy shown in the Hubble image reveal a complicated system of dust lanes and patches," Hubble astronomers said. "These are thought to be the remains of the interstellar medium associated with one or more of the spiral galaxies swallowed by NGC 1316" during the last few million years.
The NGC 1316 is a giant elliptical galaxy, not a spiral like the much smaller Milky Way, though it may have started out that way. It swelled out into a gigantic blob of dust and stars after it swallowed its first victim.

Blind Sight

2005-04-04T21:19:00.000-04:00

Researchers at Stanford University have built a "bionic eye" and started testing the device in rats. They say that the eye's vision is 20/80, sharp enough to recognize faces, watch TV, and read large print letters. They hope that in the future the eye may cure blindness in people with damaged retinas. However, they warned that human trials are at least three years away.
"Currently, there is no effective treatment for most patients with AMD (age-related macular degeneration) and RP (retinitis pigmentosa)," the researchers said. "However, if one could bypass the photoreceptors and directly stimulate the inner retina with visual signals, one might be able to restore some degree of sight."
The artificial eye works by directly stimulating the retinal layer underneath the dead photoreceptors "using a system that looks like a cousin of the high-tech visor blind engineer Lt. Geordi La Forge wore in Star Trek: The Next Generation."
The researchers said that the system consists of a tiny video camera "mounted on transparent 'virtual reality' style goggles." There's also a wallet-sized computer processor, a solar-powered battery implanted in the iris and a half a rice grain-sized light-sensing chip implanted in the retina. The chip allows users to perceive 10 degrees of visual field at a time.
Artificial eyes had already been designed in Germany, Japan, and elsewhere in the U.S. But the Stanford researchers say it achieves the highest clarity by making the most of the eye's natural image-processing strengths by subretinal placement of implants," as well as "tracking rapid intermittent eye movements required for natural image perception."

Pie in The Sky

2005-04-01T21:04:00.000-05:00

Astronomers probing the Milky Way with an X-ray satellite telescope have found a gigantic "natural" particle accelerator suspended like a halo above the Arches cluster, the largest star forming region in our galaxy.
Resembling a huge hula hoop, the accelerator has a circumference of some 60 light years. Particles racing on this cosmic autobahn achieve velocities near the speed of light and energies thousand times higher than its earthly counterparts in Brookhaven, Fermilab, or CERN.
Masaaki Sakano from the University of Leicester, U.K. said that most X-ray emissions in the universe are the residual radiation of some cataclysmic event like supernova explosion and have a characteristic temperature. "However, in this case the loop is non-thermal and this means that whatever the origin of the structure is, it is not stationary but rather the result of some ongoing process," Sakano said.
The scientists said that they weren't sure whether the structure was "physically related to the Arches cluster or just happens to be in our line of sight."
The cluster made a splash last month when astronomers studying Arches stars with the Hubble Space Telescopes found that stars have a weight limit: they can't get any fatter than 150 solar masses. (See The Skinny on Fat Stars.)

Dark Clouds Over Black Holes?

2005-03-31T06:53:00.000-05:00

Over the last 80 years, few topics ignited more bitter squabbling among eminent physicists than black holes. Einstein didn't believe in them. Chandrasekhar did but never recovered his balance after he clashed with Eddington, who didn't. Oppenheimer proved their existence, only to have his claims publicly doubted by Wheeler, who paradoxically coined the term black hole. Hawking was a believer, he even showed how they eventually evaporate. The issue seemed settled.
But now George Chapline, scientist at the Lawrence Livermore National Laboratory says that black holes violate the laws of quantum physics and cannot exists. He says that the objects are instead dark energy stars, made of the mysterious invisible stuff that fills up 75% of the universe. [The remaining 20% is dark matter and 5% visible matter.] "Event horizons and closed, time-like curves cannot exists in the real world for the simple reason that they are inconsistent with quantum mechanics," wrote Chapline. Rather than spacetime singularities, Chapline says that black holes are really huge gobs of dark energy . He posits that these gobs, formerly known as black holes, might actually be the missing mass of the universe.
Under accepted theory, an imploding star of multiple solar masses will collapse into a rock of zero volume and infinite density. But we can never see the rock. It will be hidden from view by so called event horizon, predicted by Einstein's general relativity, where time freezes and beyond which there's no point of return.
However, Chapline says no such collapse can take place. He argues that an event horizon marks the space where regular visible matter undergoes a "phase transition" into a "compact object" made of dark energy. He says: "I call such a object a 'dark energy star.'"

Shaken and Starred

2005-03-30T23:22:00.000-05:00

Astronomers at the European Space Agency say they have evidence that shock waves unleashed by titanic galactic collisions stirred up clouds of hydrogen gas and ignited the first stars when the universe was just a billion years old.
The ESA teams trained their Infrared Space Observatory telescope at a pair of colliding galaxies called Antennae, some 60 million light years away. They noticed that overlapping regions of the galaxies were packed with vibrating hydrogen atoms.
The scientists believe that the images explain how shock waves produced by galactic collisions in the early universe "excited" clouds of hydrogen and helium and ignited the first stars. "These objects... would otherwise have taken much longer to form, since light elements such as hydrogen and helium take a long time to cool down and condense into a proto-star," ESA said in a press release. "Shock waves from the first cloud collisions may have been the helping hand."

The Big Chill

2005-03-29T21:39:00.000-05:00

Scientists at MIT and the Woods Hole Oceanographic Institution on Cape Cod say that ice ages, which come and go every 100,000 years, are driven by the tilt of the Earth's axis.
They say that the angle between Earth's equatorial and orbital planes, called obliquity, shifts between 22.5 and 24 degrees every 41,000 years. They built a model that shows that as the tilt increases and the planet tips to the side like a poorly balanced sinker, more sunlight can reach high latitudes and thaw glaciers.
Since Earth is tipped now at 23.5 degrees and moving up, danger is some cool weather may be heading our way. Praise global warming for each balmy day, the scientists say. "Without the much more rapid anthropogenic or human influences on climate, Earth would probably be slowly moving toward glaciation," they say in a press release.
One mystery remains: Since the tilt switches every 41,000 year, how come the ice age cycle lasts 100,000 years? The scientists propose that glaciers must first grow large before they are sensitive to tilt changes.

Pale Blue Dot

2005-03-28T22:15:00.001-05:00

Here's a picture of the Earth snapped by the Voyager from 4 billion miles away. It's a dated shot, taken in 1991, but it doesn't grow old. Here we are, clinging to a speck of dust in the vast cosmic emptiness, yet never in doubt that we are special.

Black Hole in New York?

2005-03-27T22:43:00.000-05:00

Here's a first: a U.S. particle accelerator has produced a "fireball" similar to a tiny black hole. Horatiu Nastase, physicist at Brown University in Rhode Island, has published a paper saying that by smashing gold nuclei traveling at speeds near the speed of light the Relativistic Heavy Ion Collider in Brookhaven, New York made a fireball that was "the analog of a dual black hole." (see Black Hole Factory, Feb. 21)
Here's the catch: by analog he means "completely different from a black hole in the real universe; in particular, it cannot grow by gobbling up matter." He says that "because the amount of matter created at RHIC is so tiny, RHIC does not, and cannot possibly, produce a true, star-swallowing black hole."
In a nut, it's still not completely clear what the scientists at RHIC saw. Horatiu says that his fireball is just "mathematically similar" to a "real" black hole. Mathematically similar means that Nastase had to describe the fireball in 10 dimesions to make it look like a black hole. The black hole is "dual" becasue Nastase created a mathematical link between the "real" fireball and the imaginary 10-dimesional hole. Stay tuned for more details.
The New York Times published a nice wrap up on March 29.

Cracking Killer Flu

2005-03-25T21:22:00.000-05:00

Scientists at the National Institute of Allergy and Infectious Diseases in Bethesda, Maryland have started recruiting 450 volunteers to test the safety of a new vaccine against the lethal bird flu brewing in Asia.
The flu emerged in Hong Kong in 1997 and has spread among poultry populations in Vietnam, Thailand and elsewhere in Asia. So far it has infected 69 people who had come in contact with sick animals, and killed 46 of them, a chilling 67% mortality rate.
Health officials around the world have been sounding alarms, saying that the flu virus, labeled H5N1, could spark global influenza pandemic like the one in 1918, which killed 50 million people. Doctors in the U.S. says that even a relatively mild strain would kill over 200,000 Americans.
The drug maker Sanofi Pasteur made the new trial vaccine using an inactivated H5N1 virus isolated in Southeast Asia in 2004. The company didn't release any other production details.
The NIAID trial will test the vaccine's safety and ability to generate an immune response in 450 healthy adults aged 18 to 64. If the vaccine is shown to be safe in adults, there are plans to test it in other populations, such as the elderly and children.
Separately, Scientist at the British National Institute for Biological Standards and Control have also managed to build a vaccine against the H5N1. The NIBSC is due to present its report on the vaccine at the U.K.'s Society for General Microbiology on April 6.

Sprite Hunting

2005-03-24T08:14:00.000-05:00

Lightning sprites, faint, colorful and exceedingly brief flashes of light that shoot up above thunderheads as high as 50 miles, have been long veiled in mystery. They've been reported by pilots and flyers, but since they last only a few miliseconds they've never been filmed or photographed.
Now researchers at Stanford University say they've captured a few sprites on film in the skies above New Mexico. They posted the image online. The recording, made with a fast telescopic video camera, shows dynamic bead and streamer formations looking very much like the skies over Baghad a couple years ago.
Previous research by Duke University scientists has linked sprite development to powerful thunderstorms and strong cloud-to-ground lightning bolts.
Most often, sprites evolve quickly in a "very causal" way, according to Duke's Steven Cummer, "when an exceptional lightning burst builds up a high-altitude electric field sufficient to spawn a second spark, which turns into a sprite."

Meddling With Mendel

2005-03-23T07:37:00.000-05:00

Biologists at Purdue University have found a plant that defies the 150-year old Mendelian inheritance laws and contradicts some of the most fundamental tenets of genetics.
The plant in question was able fix a mutant gene passed on by both parents. It simply skipped a generation and reverted to a healthy state of its grandparents. "This means that inheritance can happen more flexibly than we thought in the past," said Robert Pruitt, a molecular geneticist at Purdue. "While Mendel's laws that we learned in high school still are fundamentally correct, they're not absolute."
The scientists kept the plants, called Arabidopsis, in isolation so they couldn't accidentally crossbreed with plants that didn't have the mutated gene. Pruitt said that Arabidopsis have somehow kept a "cryptic copy of everything that was in the previous generation, even though it doesn't show up in the DNA, it's not in the chromosome. Some other type of gene sequence information that we don't really understand yet is modifying the inherited traits."
There's already talk that DNA may not be the only carrier of genetic information and the driver of evolution. Scientists have proposed that genes may be also passed by the less stable strands of DNA's cousin, RNA.

Stars On Steroids

2005-03-22T21:25:00.000-05:00

Astronomers at the European Southern Observatory have found a dazzling "super star cluster" shimmering with 500,000 brilliant young stars, some quite bizarre. The stars, many a thousand times bigger than the Sun, are packed like colorful marbles inside a tiny pocket of the Milky Way just six light years across. "If the Sun were located at the heart of this remarkable cluster, our sky would be full of hundreds of stars as bright as the full moon," ESO scientists said.
The cluster, called Westerlund 1, contains thousands of "monster stars," orbs that would fill up the solar system all the way to Saturn's orbit. There are superhot Wolf-Rayet stars, even Yellow Hypergiants, a type of star never before seen in our galaxy and as bright as a million Suns.
The cluster is located in the southern skies in the constellation Ara, just 10,000 light years away. The Westerlund stars are all very young, 3.5 to 5 million years old. [Our Sun is 4.5 billion years old.] Astronomers hope to learn from them how massive stars form and die.
Since there are so many big stars so close together, some of them may collide and form black holes. Others will go supernova, as many as 1,500 over the next 40 million years.
The cluster was discovered in 1961. But most of its stars were hiding under a thick blanket of interstellar gas that was only recently pulled off with new generation of telescopes.

Space Junk

2005-03-21T22:38:00.000-05:00

A sobering image released by the European Space Agency shows how much "space debris," i.e. old satellites and other man-made garbage litters the Earth's orbit.
There are 8,700 objects in orbit that are larger than four inches and therefore "observable," but only 7% are operational spacecraft, ESA says. A full half are decommissioned satellites, spent upper rocket stages, and mission related objects like lens covers. The remaining 43% is detritus from 160 spacecraft orbital explosions recorded since 1961.
These explosions have also generated as many as 150,000 pieces of smaller junk one half to ten inches long. It's this debris that worries rocket engineers. "These are too small and numerous to be individually tracked but could cripple or kill any craft they hit," ESA says. Since they can't be seen, scientists have to rely on sophisticated probability models and software to navigate through the orbiting landfill.
"If you calculate the combined profile area of all satellites in orbit, you find that the average time between destructive collisions is about 10 years," said Heiner Klinkrad, ESA debris specialist. "It's now standard practice that near-Earth satellites carry an allowance of fuel simply for taking evasive manoeuvres during the craft's operational lifetime."

Pumping Iron

2005-03-20T21:13:00.000-05:00

Just last week a California company announced it developed blood-borne metallic nanodust that could slip inside the tiniest capillaries and revolutionize magnetic resonance imaging(see In Dust They Trust). Now a group of biochemists from Carnegie Mellon University may have something even better.
The scientists say they have found a way to genetically program cells to make their own MRI markers. They say that the method will allow doctors visualize gene therapy and track where genetic drugs travel in patients.
Patients who need an MRI scan of the brain, the vascular system, or other body parts get injected with dyes, or contrast agents, to improve image quality. But dye molecules are too clunky and can't penetrate everywhere.
The Mellon approach uses an emasculated virus as a vehicle to carry a gene that makes ferritin, a "metalloprotein" which the body uses to store iron. The virus tricks targeted cells into producing their own ferritin. Since ferritin carries iron, its molecules act like nano-magnets and strong MRI markers.
"Our technology is adaptable to monitor gene expression in many tissue types," said Eric Ahrens, assistant professor of biological sciences in the Mellon College of Science. "You could link this MRI reporter gene to any other gene of interest, including therapeutic genes for diseases like cancer and arthritis, to detect where and when they are being expressed."
The Mellon report appears in the April issue of the Nature Medicine journal.

Mean Piece of Ice

2005-03-18T19:22:00.000-05:00

New pictures from the Envisat satellite show that B-15A,currently the world's largest free-floating iceberg, is moving again. The cucumber-shaped iceberg is the size of a small European country - 75 miles long and 13 miles wide.
The giant floe cracked off the B-15, the largest iceberg ever observed, near the Ross Ice Shelf in Antarctica in 2000. While its parent, which was the size of Jamaica, quickly disintegrated, B-15A remained remarkably sturdy, bullying the freezing Antarctic seas. For over two years it diverted sea currents, disrupted breeding patterns for a penguin colony and required extra icebreaker activity to maintain shipping routes.
During a vicious storm in 2003, B-15A got stuck on an Antarctic shelf 2,400 miles south of New Zealand. A piece of the berg broke off during the storm, but the bulk remained intact.
Scientists at the European Space Agency, which operates Envisat, say that in early March tides and local currents lifted the rogue berg and set it free again. Already, it nearly caused a titanic ice collision, dodging the 40-mile-long Drygalski ice tongue in McMurdo Sound on the Ross Sea by just a few kilometers.

In Dust They Trust

2005-03-17T07:20:00.000-05:00

The nanotech company QuantumSphere said it has developed nanodust that can travel through the human body and dramatically improve the quality of magnetic resonance imaging.
The particles, which circulate in the blood, are many times smaller than blood cells and can penetrate the tiniest blood vessels and cavities. Since they are also magnetic, they can focus the MRI's electromagnetic waves and improve images of internal organs "on the orders-of-magnitude" compared to existing methods.
The dust is blended with blood and the mix is injected in the bloodstream.
The nanomaterial is now going through Phase I animal testing. Assuming QuantumSphere gets the invention approved by the FDA, the dust could be a huge deal for brain imaging and treating brain disease like brain tumors, epilepsy, Alzheimer's disease. The particles could be used to show "functional" detailed images of the brain in action.

Seeing In The Dark

2005-03-16T20:54:00.001-05:00

Astrophysicists at the University of Washington have used a supercomputer to create the first image of the mysterious dark energy that makes up three quarters of the mass of the universe. Strangely, the picture evokes an image of brain tissue with bright dots of galaxies illuminating the centers of neuron-like tangles of visible matter. Dark energy roils in the voids between the filaments. The image shows a segment of the universe 2.8 billion light years wide, 2.6 billion light tall, and 290 million light years thick.
The picture stemmed from data gathered by astrophysicists Andrea V. Maccio, Fabio Governato and Cathy Horellou. Their paper on dark energy flow in our cosmic neighborhood called the Local Group, which includes the Milky Way, the Andromeda Galaxy, and a number of other smaller galaxies, was just submitted to the to the Monthly Notices of the Royal Astronomical Society.

Legally Human

2005-03-15T22:36:00.000-05:00

Researchers from Yale and Vanderbilt Universities argue that biologists and neuroscientists should be involved in drafting new laws. "Laws and public policy will often miss their mark until they incorporate an understanding of why, biologically, humans behave as they do," they said
Vanderbilt law professor and biologist Owen Jones said that "the legal system tends to assume that either people are purely rational actors or that their brains are blank slates on which culture and only culture is written. The reality is much more complicated and can only be appreciated with a deeper understanding of behavioral biology."
Writing in a paper published in the current issue of the Columbia Law Review, the researchers said that "legislators and legal scholars have traditionally relied heavily on the social sciences, such as economics, psychology and political science, often responding to the popular or political trends of their time. They have rarely looked to incorporate the latest findings from fields such as biology, neuroscience and cognitive psychology, which...have shed brand new light on how the human brain is structured and how it influences behavior."

Dating Disaster

2005-03-14T20:08:00.000-05:00

Two American researchers have dug up evidence that life's diversity on Earth gets periodically wiped out "in mysterious cycles of 62 million years for which science has no satisfactory explanation."
Physicists Richard Muller and Robert Rohde working at the U.S. Department of Energy's Lawrence Berkeley National Laboratory and the University of California at Berkeley have analyzed the fossils of 36,380 marine animals living over the past 542 million years. They discovered the cycle by creating an extensive computer database and analyzing the various genera. "What we're seeing is a real and very strong signal that the history of life on our planet has been shaped by a 62 million year cycle, but nothing in present evolutionary theory accounts for it," said Muller.
The researchers speculate that either periodic asteroid showers or cataclysmic volcanic eruptions may be behind the cyclical mass death. "My hunch, far from proven," Rohde said," is that every 62 million years the earth is releasing a burst of heat in the form of a plume formation event, and that when those plumes reach the surface they result in a major episode of flood volcanism. Such volcanism certainly has the potential to cause extinctions, but, right now there isn't enough geologic evidence to know whether flood basalts or plumes have been recurring at the right frequency."
Muller suspects comets. They "could be perturbed from the Oort cloud by the periodic passage of the solar system through molecular clouds, Galactic arms, or some other structure with strong gravitational influence," he said. "But there is no evidence even suggesting that such a structure exists."
Their report appears in the current issue of Nature

Mob Management

2005-03-13T21:47:00.000-05:00

Chemists at the University of Wisconsin in Madison are working on miniscule chemical warfare agents that can disrupt communication between bacteria and prevent disease outbreak.
The scientists said their goal was to thwart the rise of "bacterial mobs," more mundanely known as biofilms. Such dangerous bug colonies thrive in hospitals and are sometimes resistant to the most powerful antibiotics. They can cause many lethal infections, like attacking the lungs of post-op cystic fibrosis patients, even crop up on sterilized medical implants.
The scientists said the bug mobs "have long baffled doctors because of their stupefying capacity to behave like a 'super-organism' that vetoes the normal characteristics of a bacterial cell in favor of new group behaviors." Said team member Helen Blackwell: "It's amazing that such simple organisms as bacteria can form these super-colonies that work together in such sophisticated ways."
Trying to outsmart the bugs, the scientists learned that germs sense each other and the overall density of their colony "by continuously exchanging small molecules [called acylated homoserine lactones] and peptides - a process known as quorum sensing. Past a certain density threshold, the colonies unite to initiate group behaviors, such as biofilm formation." Hence the researchers started working on chemicals to disrupt the communication and hijack the mob by piping in their own commands. "We want to design molecules to confuse bacteria so they can't sense their neighbors," says Blackwell, "but some types of quorum sensing are beneficial, so we are simultaneously searching for compounds that selectively turn on group behaviors."
The findings have been presented today at the national meeting of the American Chemical Society held in San Diego.

The Skinny on Fat Stars

2005-03-12T21:16:00.000-05:00

Astronomers using the Hubble Space Telescope say they've measured how fat a star can get. Studying the densest known star cluster in the Milky Way galaxy, the Arches cluster, they determined that stars can't get any larger than about 150 times the mass of our Sun, or 150 solar masses. That's a barely bare bones image of the burning behemoths they expected to find
"Standard theories predict 20 to 30 stars in the Arches cluster with masses between 130 and 1,000 solar masses, but we found none" said Donald F. Figer of the Space Telescope Science Institute in Baltimore, Md. "If they had formed, we would have seen them."
The discovery that stars have a weight limit offers an important to clue to how stars form, burn and die. "Even with the advances in technology, astronomers do not know enough about the details of the star-formation process to determine an upper-mass limit for stars," said Figer.
Astronomers have been debating for at least a century how large a star can get before it blows itself apart. Stars are cosmic foundries forging hydrogen into heavier atoms like carbon, oxygen, iron and all the rest of the elements that make people, dogs, trees and the rest the the visible universe. The elements scatter through space when stars go supernova in a cataclysmic explosion.
Figer spent seven years studying the Archer cluster. His paper appears in the current issue of Nature.

Running With The Wrong Crowd

2005-03-11T19:13:00.000-05:00

The Hubble Space Telescope has snapped a series of pictures of a small galaxy laden with newborn stars that is being ripped to pieces by a gang of bigger peers. The galaxy NGC 1427A, which is 62 million light years away, strayed too close to a group of large galaxies in the Fornax cluster. The galaxy is being pulled by the gang's gravity, plunging headlong into the Fornax group at 400 miles per second.
Hubble astronomers said that NGC 1427A will not "survive long as an identifiable galaxy. Within the next billion years, it will be completely disrupted, spilling its stars and remaining gas into intergalactic space."

Double Trouble

2005-03-10T07:33:00.000-05:00

Two adjacent volcanoes blew off nearly simultaneously on the Russian peninsula Kamchatka earlier this year. The freak incident was caught on camera by the European Space Agency's Envisat MERIS satellite on March 7. One of the volcanoes, Kliuchevskoi, is Kamchatka's highest, towering 4,835 meters. It's comparable in size to Washington's Mt. Rainier. The other volcano, Sheveluch, is 3282 meters high. Kamchatka is one of the world's most volcanically active regions. Some 60 volcanoes are located in the vicinity.

Death's Lease on Life Decoded

2005-03-10T06:08:00.000-05:00

Biochemists at the University of California, Los Angeles have unlocked the structure of telomerase, the enzyme that's been called the "biochemical elixir of youth and immortality," but which also fuels the malignant growth of cancer cells.
This is a big deal since telomerase has been so hard to find in human cells that some scientists referred to it as "that mythical enzyme."
Here's what it does: Each set of chromosomes is framed by a protective cap of DNA called a telomere. Telomeres make sure that when cells divide, no meaningful DNA sequence gets left out. But telomeres are also resposinble for shutting down old cells, i.e. aging. Like slow-burning blasting fuses, they shorten each time a cell divides. Once a telomere runs out, the cell shuts down and dies. Along with it die potentially cancerous mutations the cell accumulated with old age. But telomerase reverses this process. The enzyme restores the length of the caps and makes cells effectively immortal.
It sounds great but it's quite dangerous. That's why telomerase is turned off in the vast majority of cells in the body. It's only active in the developing embryo, germ cells, and cancer cells.
During cancer, active telomerase stokes malignant multiplication of cells and the growth of tumors. Understanding the chemical structure of telomerase and how to turn it off could launch development of new cancer drugs. "Knowledge of the structure should provide insights into how telomerase works," said Juli Feigon, professor of chemistry and biochemistry at UCLA, who led the research group. "Knowing the structure also will allow the pursuit of rational, structure-based drug design, and is a critical first step. The structure provides a potential target for drug intervention."
Feigon's findings were published in the March 4 issue of the Molecular Cell journal.

A Home in the Universe

2005-03-09T05:58:00.000-05:00

Pictures of the Earth never fail to amaze. Enjoy the latest set snapped in stylish black and white by the Rosetta spacecraft as it swung by us on March 4. The Rosetta took the pictures from 1,200 miles away as it was leaving towards a rendezvous with Comet 67P/Churyumov-Gerasimenko. The date will not take place until 2014, though.
In the meantime, Rosetta is using the Earth and Mars as gravitational slings to push itself on.
The Rosetta launched in 2004. The European Space Agency built it for long-term close-range comet exploration. The Rosetta carries a large orbiter, which is designed to operate for a decade at large distances from the Sun, and a small lander.

Some Say the World Was Born In Ice

2005-03-08T06:26:00.000-05:00

Here's the theory behind the start of the solar system. In the beginning, some 6 billion years ago, there was blinding light from a nearby supernova. Shockwaves from explosion stirred a large cloud of interstellar gas. The gas collapsed at the cloud's center, igniting the precursor of our Sun (see below Wee Star Found.) Turbulence within the gas cloud gave birth to mile-wide clumps of micron-sized dust, which later grew into planets.
Here's the problem with the scenario. When scientist tried to recreate those conditions, the dust particles bounced "like two billiards balls smacked together." The protoplanets should have never formed.
Now physicists from the U.S. Department of Energy say found an answer to the enigma. The baby planets were held together by cosmic glue made of miniscule grains of sticky ice. Writing the latest issue of the Astrophysical Journal, the scientists say that the dust was "encrusted with molecularly gluey ice" that enabled planets to "bulk up like dirty snowballs quickly enough to overcome the scattering force of solar winds."
James Cowin of the DOE's Pacific Northwest National Lab and leader of the team said that "this ice [was] very different from the stuff we chip off our windows in winter." At extremely low temperatures, between 5-100 Kelvin, the ice spontaneously becomes electrically polarized, pulling the grains together like little bar magnets.
At such low temperatures the ice grains become "fluffy," forming tiny "billiard balls made of Rice Krispies" that barely bounce. Such colliding snowballs would have enough electrical force to stop them from crumbling, as well as enough cushioning to survive the crashes and grow into large lumps, Cowin said.
Today, vestiges of this icy conception remain inside planets like Jupiter, comets, and the far reaches of the solar system.
Cowin "speculates" that similar forces might have been at work during the infancy of hotter inner planets like the Earth, involving silicate dust grains instead of ice.

Black Hole Violence

2005-03-07T20:41:00.000-05:00

Scientists at Johns Hopkins University have created a powerful computer program that simulates how matter falls into a black hole. They expected smooth and quiet demise of matter as it nears the hole's event horizon, the point of no return where Newtonian laws of gravity break down. Instead, the simulation, which the scientists posted on the internet, shows the falling matter flaring violently like a seething Mandelbrot set.
"Life in the vicinity of a black hole is anything but calm and quiet," the scientists said. "The relativistic effects that force matter to plunge inward ... create violent disturbances in density, velocity and magnetic field strength, driving waves of matter and magnetic field to and fro. While most of the matter moves inward toward the black hole, some is thrown away, spiraling outward at nearly the speed of light."

Eraser Head

2005-03-07T06:09:00.000-05:00

Michael Antle, neuroscientist at the University of Calgary, has found the body's clockwork. The timepiece, called the human circadian clock, is located in the suprachiasmatic nucleus of the brain. Reporting in the current issue of the Trends in Neurosciences journal, Antle said the clock is a tiny tangle of 20,000 time-keeping neurons no bigger than "half the size of pencil eraser." Antle said that the cells are organized "in a complex network of groups," each performing a different function, like a distributed computer network.
The circadian clock tells us when to go to bed, when to wake up, and is responsible for jet lags.
Antle said he will next try to reset the clock by changing levels of the neurotransmitter serotonin. But he cautioned that we were "probably still at least 10 years away from developing a pill that could reset the brain clock to eliminate jet lag, but this new perspective in how the cells are organized definitely improves our understanding."
All terrestrial organisms, even single-celled organisms, have circadian rhythms. Antle says that for every hour of time change a person experiences it takes about a day to fully adjust.

Wee Star Seen

2005-03-05T21:51:00.000-05:00

Scientists from the European Space Agency and NASA observed for the first time a stellar embryo in a collapsing cloud of hydrogen gas. They said that that the images were "analogous to a baby's first ultrasound."
Using the ESA's XMM-Newton X-ray telescope and NASA's Chandra X-ray Observatory, they said that the object, some 500 light years from Earth in the R Corona Australis star-forming region, is a frigid embryonic star, called a Class 0 protostar. Class 0 protostar is just 10 000 to 100 000 years old. The stellar weather inside the cloud is freezing 33 K (-240 C).
But here's the riddle. The team said that the cloud was too cold to produce X-rays and that "matter [was] falling toward the protostar core 10 times faster than expected from gravity alone." According to accepted models, it takes millions years and a lot of hot dense hydrogen gas to fire up a new star and start belching X-rays.
The scientists now believe that the X-ray bursts were caused by magnetic fields, which "in the spinning protostar core accelerate infalling matter to high speeds, producing high temperatures and X-rays in the process. These X- rays can penetrate the dusty region to reveal the core."

Planet Quest

2005-03-04T19:09:00.000-05:00

A decade ago, the spottings of new planets outside our solar system made front-page news. But as more and more orbs started popping out in the sky, their visibility to the general public dimmed.
The planet hunt is still on, though. Big time. Just this year, astronomers have already discovered 11 planets. In total, we've found 152 planets and 134 planetary systems with one or more planets. One planet, called TrES-1b might even have rings like our neighbor Saturn.
Some stargazers have started searching for habitable planets, which are defined as having a temperature of about 300K to allow for liquid water.
Many of the observations have been made by amateur astronomers with backyard telescopes. For a complete tally, and planet detection methods check out the Extrasolar Planets Encyclopaedia.

Forget Asteroids, Fear Volcanoes

2005-03-04T06:22:00.000-05:00

The Geological Society of London have told the British Government that catastrophic volcanic eruptions "might threaten global civilzation." It said that such eruption, hundreds times larger than Krakatoa, would cause damage comparable to the impact of a 1 kilometer asteroid, but is 5 to 10 times more likely. "Such eruptions are quite frequent on a 'geological' timescale, although not one has occurred on Earth in the short time that an interdependent human civilisation has existed," the society said. "There may be several super-eruptions large enough to cause a global disaster every 100,000 years. This means super-eruptions are a significant global humanitarian hazard. They occur more frequently than impacts of asteroids and comets of comparable damage potential."
Prof. Steve Sparks of the University of Bristol, co-lead author of the report, said: "Several of the largest volcanic eruptions of the last few hundred years, such as Tambora (1815), Krakatoa (1883) and Pinatubo (1991) have caused major climatic anomalies in the two to three years after the eruption by creating a cloud of sulphuric acid droplets in the upper atmosphere. These droplets reflect and absorb sunlight, and absorb heat from the Earth - warming the upper atmosphere and cooling the lower atmosphere. The global climate system is disturbed, resulting in pronounced, anomalous warming and cooling of different parts of the Earth at different times."
The detailed report is still under embargo. But last month, American scientists reported that huge volcanic eruptions in Siberia some 250 million years ago may have caused mass extinction of plants and animals.

The Universe Got Old Young

2005-03-04T05:18:00.000-05:00

Astronomers at the European Southern Observatory have watched the most distant object in the known Universe. The object is a remote cluster of galaxies that weigh as much as several thousand galaxies like our own Milky Way. It hovers 9 billion light years away. That's 500 million light years farther out than the previous record holding cluster.
The cluster must have formed when the Universe was less than one third of its present age, just 4.7 billion years after the big bang. (The Universe is thought to be 13,7 billion years old.)
The discovery of such a complex and mature structure so early in the history of the Universe is "highly surprising," the scientists said. "Until recently it would even have been deemed impossible."
Clusters of galaxies are gigantic structures containing hundreds to thousands of galaxies. They are the fundamental building blocks of the Universe. They give us clues about the underlying architecture of the Universe as a whole. (Our Milky Way galaxy, for example, belongs to the Virgo supercluster.)
"We seem to have underestimated how quickly the early Universe matured into its present-day state," said Piero Rosati, a member of the ESO team. "The Universe did grow up fast!"

Quantum Quandary

2005-03-04T04:30:00.000-05:00

Emmanuel Knill from the National Institutes of Standards and Technology has come up with a way to eliminate errors from quantum computers. Such supercomputers are the holy grail of everyone hobbled by inadequate computer speed. But prototypes have been woefully unrealiable. Knill's solution could make such machines work.
Ordinary computers use millions of transistors on a chip to perform mathematical and logical operations. The transistors talk to each other in words, or bits, of binary code, switching on and off to telegraph 0s and 1s. Quantum computers would use properties of individual atoms, such as their spin and magnetic properties, to do the same and compute at untold speeds. A quantum binary word is called a qubit.
But there's a hitch. Qubits are very prone to outside electronic noise and can easily get garbled. Knill's solved the problem by building a pyramid-style hierarchy of qubits, and teleportation of data at key intervals to continuously double-check the accuracy of qubit values. That's right, teleportation. It's one of the many odd behaviors permited on the atomic scale level by the laws of quantum mechanics. Last year, NIST physicists showed that teleporting works. They transferred key properties of one atom to another atom without using a physical link.
"There has been a tremendous gap between theory and experiment in quantum computing," Knill says. "It is as if we were designing today's supercomputers in the era of vacuum tube computing, before the invention of transistors. This work reduces the gap, showing that building quantum computers may be easier than we thought. However, it will still take a lot of work to build a useful quantum computer."

Killing Immortality

2005-02-28T04:34:00.000-05:00

French biologists say thay have proof that immortality is impossible. Single-celled bacteria like E. coli, and even some humans, have long nutrured hope that they may eascape aging and death. No so, says Eric J. Stewart of the Institut des Hautes Etudes Scientifique in France. "No life strategy is immune to the effects of aging and suggest that this may be because immortality is too costly or is mechanistically impossible," he writes. "This may be bad news for people who had hoped that advances in science might eventually lead to human immortality."
Scientists have assumed that cells that divide symmetrically do not age and are functionally immortal. Stewart and his colleagues tested this idea by analyzing repeated cycles of reproduction in Escherichia coli, a bacteria that reproduces without a juvenile phase and with an apparently symmetric division.
E. coli is a rod-shaped organism that reproduces by dividing in the middle. Each resultant cell, Stewart writes, inherits an old end or pole and a new pole, which is made during the division. The new and the old pole contain slightly different components, so although they look the same, they are physiologically asymmetrical.
Stewart found that the cells "inheriting old poles had a reduced growth rate, decreased rate of offspring formation, and increased risk of dying compared with the cells inheriting new poles. Thus, although the cells produced when E. coli divide look identical, they are functionally asymmetric, and the old pole cell is effectively an aging parent repeatedly producing rejuvenated offspring."
That may take some wind from the sails of transhumanists and others who believe in the possibility of immortality in some shape.
At least Stewart did try to offer some solace. He said his research provides "an excellent genetic platform for the study of the fundamental mechanisms of cellular aging and so could provide information that might ameliorate some of the unpleasantness of the human aging process."

Supernova Caught on Film

2005-02-26T13:14:00.000-05:00

European astromomers at the Calar Alto Observatory in Spain have caught a dazzling supernova on film. The exploding star resides near the edge of the spectacular "grand spiral galaxy" NGC 6118 some 80 million light years away. The supernova blew up on August 1, 2004. Acccording to the astronomers, this particular kind of supernova resulted from the demise of a massive star that has lost its entire hydrogen envelope.
The supernova was classified Type Ib or Ic, which means it was part of a binary star system. A binary system involves a regular star,like our sun, and a super dense star called white dwarf. The heavy dwarf sucks away hydrogen from the neighboring star, fattening itself until it suffers from a massive case of indigestion (reaches critical density) and blows off. Such stellars explosions fuse hydrogen into helium, oxygen, carbon, iron, and so on, forging all the elements you, I, even the beer in your fridge are all made of.
Click on the headline for a picture.

Galactic Pile-up

2005-02-24T21:24:00.000-05:00

Astronomers from the European Southern Observatory reported that our neighbor the Andromeda Galaxy and most other spiral galaxies are the result of titanic galactic collisions that took place some 8 billion years ago. The reigning theory has been that galaxy formation ended by then.
They also say that at least half the starts visible in the night sky were produced four to eight billion years ago in "episodic bursts of intense star formation," during the galactic mergers when the galaxies were still active star hatcheries.
In a twist, they also say that our own Milky Way somehow escaped these crashes. Click on the headline for collision details.

Brain Storm

2005-02-24T01:32:00.000-05:00

Researchers at the University of California, Berkeley applied mathematical models normally used to spot trends in the stock market, weather and other complex random events to track "electrical storms" in the human brain during epileptic seizures. They hope that the results will point them to methods to stop seizures and move treatment beyond lobectomies.
The researchers found that during a seizure, "a strong pattern of electrical signals suddenly emerges from the random fluctuations that characterize normal brain activity." The strong waves moving across the cortex may cause sudden, unpredictable sensations or uncontrollable movements. "Normal brain waves would resemble jagged lines with no apparent pattern or order on an electroencephalogram (EEG)," said Andrew Szeri, UC Berkeley professor of mechanical engineering and applied science and technology, and principal investigator of the study. "But in the brains of epilepsy patients, the spreading of a seizure is made manifest by strong coherent waves of electrical activity in the cortex."
The mathematical model used stochastic partial differential equations to describe the architecture of the brain. "The model could provide insight into the pathophysiology of the spread of a seizure," said Heidi Kirsch, assistant professor of neurology at UC San Francisco's Epilepsy Center. "Further down the line, this could also help us model the impact of medications and other interventions, to theoretically test how drugs with certain mechanisms will impact the brain."
Examples of potential therapies to stop seizures include "focal cooling, in which the part of the brain experiencing a seizure is literally chilled to dampen the seizure, and electrical stimulation of the affected area of the brain to counter the seizure as it's forming."

Mysterious Invisible Galaxy Found

2005-02-23T19:15:00.000-05:00

Astronomers from Cardiff University in England have discovered an invisible galaxy. The galaxy is made of dark matter, the mysterious stuff that accounts for 25% of the universe. No one has ever seen dark matter. It's existence has only been inferred from the motion of galaxies.
The scientists used radio emissions to identify the object. The galaxy, called VIRGOHI21, is about 50 million light years away in the Virgo cluster. It's basically a giant invisible whirlpool that rotates like our Milky Way but contains no stars. "When you have eliminated the impossible, whatever is left - however implausible - must be the truth," said team member Mike Disney, quoting Sherlock Holmes.
Roughly 5% of the universe is made of visible matter, the stuff that makes you and I, your mother-in-law, and the stars, about 25% is dark matter and the rest is dark energy. No one has ever seen the latter two and we have no idea what they are. Even our galaxy is chock full of the mysterious stuff since otherwise it would fly apart like a carousel that's spinning too fast.