Jupiter’s second largest moon has a lifeless look about it. About 2.6 times smaller than Earth, Callisto is heavily cratered. It has a thin carbon dioxide atmosphere. For decades it was thought to be ...

If there was a contest for the most interesting moon in our solar system, Callisto would be a contender. Jupiter's second-largest moon has more impact craters on its surface than any other planetary ...

Add Yahoo as a preferred source to see more of our stories on Google. Like Earth, Jupiter experiences brilliant auroras around its poles — but something funky happens with Jupiter's Galilean moons ...

A recent analysis finds up to 1,000 times more molecular oxygen than can be explained by prevailing theories about where it comes from. Eric Mack has been a CNET contributor since 2011. Eric and his ...

ESA's Mars Express orbiter captured footage of the Mars' moon Deimos pass in front of Ganymede, Europa, Jupiter, Io and Callisto (in that order). Credit: Space.com | footage credit: ESA/DLR/FU Berlin ...

Long posited as a potential human outpost in science fiction, Jupiter’s icy moon of Callisto largely remains a mystery to real life planetary scientists. As one of the least studied of Jupiter and ...

The gas giant Jupiter still dominates the constellation Taurus as it sets in the west after sunset. Jupiter now stands just to the right of Alheka (Zeta Tauri), one of the tips of the Bull’s two horns ...

New research suggests that Jupiter’s icy moons may have formed with complex organic molecules already embedded in their building blocks.

Callisto, Jupiter's second-largest moon, may have a rocky surface with an ocean beneath the surface. If there was a contest for the most interesting moon in our solar system, Callisto would be a ...