Some space scientists have started to make noise about Voyager 1 reaching the edge of the solar system. The craft, which was launched in 1977, is expected to pass out of our solar system into interstellar space.
However, scientists aren't exactly sure how we'll know when that happens.
So how will we know when we finally make it into the great unknown, and what do we hope to discover there?
LEARN MORE ABOUT VOYAGER 1
• How far can voyager 1 go? Ken Croswell in Smithsonian
• Going, Going, Still Going? Voyager 1 at Solar System's Edge - The New York Times
• Where's Voyager 1? That Depends. - The New York Times