Jupiter Rising

The planet now has 79 moons. This guy discovered 59 of them.

- Fred Guterl

BY THE TIME ASTRONOMER SCOTT SHEPPARD STARTED LOOKING AT JUPITER’S MOONS in a serious way in the 2000s, the planet had already been picked over like a Thanksgiving turkey. Galileo found four moons in 1610, another nine came in the first half of the 20th century, and the Voyager spacecraft added three more in 1979. But Sheppard had an advantage on all of them: When he was a graduate student at the University of Hawaii, astronomers started attaching highly sensitive digital cameras to telescopes. By the time Sheppard got his Ph.D. in 2004, he and his colleagues had discovered dozens of Jovian moons, as well as some around Neptune, Uranus and Saturn.

Last month, Sheppard found another 12. That brings his personal tally to 59 and the total number of Jovian moons to 79. Newsweek caught up with Sheppard, who is a faculty member of the Carnegie Institution for Science in Washington, D.C.

You watched Jupiter as a student, but lately you’re more interested in the solar system beyond Pluto.