The Voyager I space probe, launched in 1977, continues to transmit data as it approaches the edge of the solar system. NASA announced yesterday that it appears Voyager has entered a new region of space, which may be the final barrier before leaving the heliosphere and venturing into interstellar space. They don't know for sure because we've never had a spacecraft travel this far.
"Although Voyager 1 still is inside the sun's environment, we now can taste what it's like on the outside because the particles are zipping in and out on this magnetic highway," said Edward Stone, Voyager project scientist based at the California Institute of Technology, Pasadena. "We believe this is the last leg of our journey to interstellar space. Our best guess is it's likely just a few months to a couple years away. The new region isn't what we expected, but we've come to expect the unexpected from Voyager."