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 ...

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 ...

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 ...

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 ...

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 ...

James is a published author with multiple pop-history and science books to his name. He specializes in history, space, strange science, and anything out of the ordinary.View full profile James is 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, ...