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 ...

Astronomers have spotted gaseous carbon dioxide across the atmosphere of Jupiter’s second-largest moon, Callisto, hinting that it might have a much more complex carbon cycle than we thought. On Earth, ...

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 ...

Scientists simulate thermal, energetic components of Jovian magnetospheric plasma irradiating Callisto's atmosphere Differential number flux spectra for (a) protons, (b) oxygen ions, (c) sulfur ions, ...

New evidence from an old NASA mission supports the theory that Jupiter's moon Callisto is in fact an ocean world. Credit: NASA / JPL / DLR A moon of Jupiter about the size of Mercury likely has a ...

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 ...