US - Voyager 1 passes milestone

30 years and counting.

Voyager 1 is now at the outer edge of our solar system, in an area called the heliosheath, the zone where the sun's influence wanes. This region is the outer layer of the 'bubble' surrounding the sun, and no one knows how big this bubble actually is. Voyager 1 is literally venturing into the great unknown and is approaching interstellar space. Traveling at a speed of about one million miles per day, Voyager 1 could cross into interstellar space within the next 10 years.

"Interstellar space is filled with material ejected by explosions of nearby stars," Stone said. "Voyager 1 will be the first human-made object to cross into it."