(AP) — Voyager 1 has crossed a new frontier, becoming the first spacecraft ever to leave the solar system, NASA said Thursday. Thirty-six years after it was launched from Earth on a tour of the outer planets, the plutonium-powered probe is more than 11 1/2 billion miles from the sun, cruising through what scientists call interstellar space — the vast, cold emptiness between the stars, the space agency said. Voyager 1 actually made its exit more than a year ago, according to NASA. But it's not as if there's a dotted boundary line or a signpost out there, and it was not until recently that the space agency had the evidence to convince it that the spacecraft had finally plowed through the hot plasma bubble surrounding the planets and escaped the sun's influence. http://bigstory.ap.org/article/out-there-voyager-1-enters-space-between-stars