PASADENA, Calif. (AP) — Thirty-five years after leaving Earth, the Voyager 1 spacecraft is reaching for the stars.

Voyager 1 is poised to exit the solar system and enter the space between stars. When that will happen isn’t clear. But scientists say there have been signs that it is on the verge of crossing over.

It will be the first manmade object to leave the solar system.

Voyager 1 and its twin, Voyager 2, were launched in 1977 on a mission to tour Jupiter and Saturn. No one knew how long they’d live.

Voyager 2 went on to explore Uranus and Neptune. Voyager 1 used Saturn to fling itself toward the solar system’s edge.

Wednesday marks the 35th anniversary of Voyager 1′s launch.

Copyright 2012 The Associated Press.