Tuesday, May 24, 2005
Trip To The Edge
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.
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.
