Jupiter's Moon Callisto Probably Has an Ocean Under Its Surface

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 body in the solar system, and it has tons of ice on its surface as well. For decades. researchers have theorized that resting beneath Callisto's pockmarked surface is a liquid saltwater ocean that spans the entire moon. After taking a closer look at data from 30 years ago, researchers now have stronger evidence that such an ocean really does exist. A team led by Corey J. Cochrane of NASA's Planetary Interiors and Geophysics Department didn't start out looking for an ocean on Callisto. According to Cochrane, the team was working on a different project, involving scanning Neptune's moon Triton to see if it has a subsurface ocean. This presented a challenge, because of Triton's intense ionosphere, which is the last layer of the atmosphere before space begins. Since Callisto also has an inte ... Read full article.