Archit Tantia

One of the twin space probes launched 35 years ago has traveled more than 11 billion miles from Earth. The Voyager probes were originally slated just to examine Jupiter and Saturn during a five-year trip.

“So we’re getting anywhere from five to eight hours of data every day from each of these spacecraft, and it’s quite remarkable,” says Ness.

Of the two, Voyager 1 is the farthest away from Earth. Don Gurnett of the University of Iowa, who has worked on the mission since the mid-1970s, says Voyager 1’s radio signals now take more than 16 hours to reach us.

Voyager 1 can keep talking to Earth for about another decade. That’s how long the plutonium that powers it should last.