NASA’s Voyager 1 has entered a new region between our solar system and interstellar space, which scientists are calling the stagnation region. The inner edge of this region is located about 113 astronomical units (10.5 billion miles or 16.9 billion kilometers) from the sun. Voyager 1 is currently about 119 astronomical units (11 billion miles or 17.8 billion kilometers) from the sun. The exact distance to the outer edge is unknown.
The stagnation region is considered to be a kind of cosmic purgatory according to data obtained from the spacecraft during the last year. In it, the wind of charged particles streaming out from our sun has calmed, but our solar system’s magnetic field has piled up, and higher-energy particles from inside our solar system appear to be leaking out into interstellar space. At the same time, Voyager has detected a 100-fold increase in the intensity of high-energy electrons from elsewhere in the galaxy diffusing into our solar system from outside, which is another indication of the approaching boundary
There is not much time left to find out what the space between stars is. The spacecraft has passed through the heliosheath, the outer shell of the sun’s sphere of influence and is still within the heliosphere, the bubble of charged particles the sun blows around itself. Interstellar space begins at the heliopause, and scientists estimate Voyager 1 will cross this frontier around 2015.
Voyager’s magnetometer detected a doubling in the intensity of the magnetic field in the stagnation region which shows that inward pressure from interstellar space is compacting it. ”We are evidently traveling in completely new territory. Scientists had suggested previously that there might be a stagnation layer, but we weren’t sure it existed until now.,” said Rob Decker, a Voyager Low-Energy Charged Particle Instrument co-investigator at the Johns Hopkins University Applied Physics Laboratory in Laurel, MD.
Launched in 1977, Voyager 1 is about 18 billion kilometers from the sun. A signal from the ground, traveling at the speed of light, takes about 16 hours one way to reach the spacecraft. Voyager carries aboard recorded messages from Earth on golden phonograph record – 12-inch, gold-plated copper disk that contains images and natural sounds, spoken greetings in 55 languages and musical selections from different cultures and eras.
Source URL: http://www.nasa.gov/mission_pages/voyager/index.html