But the moon’s wild volcanic activity wasn’t detected until Voyager 1 flew by Jupiter and its moons in 1979, revealing Io’s dynamic surface that resembled a pepperoni pizza, Bolton said.

Voyager 1 visited Jupiter and Saturn and then kept on going and going. In 2012, it left our cosmic neighborhood and entered the space between stars. It was the first human-made object to leave our ...

Voyager 2 preceded it into space by 16 days, but Voyager 1 quickly overtook it on a faster trajectory, and arrived at Jupiter 4 months before its sister craft. Voyager 1 took this photo of Jupiter ...

The original mission was meant to last four years as the probe visited Jupiter and Saturn. It’s now spent 46 years in space, making Voyager 1 and its twin Voyager 2 the longest-operating ...