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 ...

Io orbits so close to Jupiter that gravity alone reshapes its entire surface. Instead of cooling over time, the moon is ...

The hellish surface of a moon of Jupiter known as Io is riddled with hundreds of lava-spewing volcanoes that make the world one of chaos and violence. The brutal conditions also make Io intriguing to ...

NASA Juno mission captured amazing new imagery of Jupiter's moon Europa. The spacecraft flew about 219 miles (352 kilometers) ...

Oceans hiding within the crusts of distant moons are tantalizing targets for scientists looking for life beyond Earth ...

Forbes contributors publish independent expert analyses and insights. An award-winning reporter writing about stargazing and the night sky. Io, the innermost giant moon of Jupiter, may not have a ...

More pocked with craters than any other object in our solar system, Jupiter's outermost and second-biggest Galilean moon, Callisto, appears geologically unremarkable. In the 1990s, however, NASA's ...

Jupiter’s moon Io is a hotbed of geological activity, with over 400 active volcanoes. Because of this high level of activity, scientists have been debating for years about what’s going on under the ...

If there's no magma ocean, where does the 'melt' come from that emerges from the volcanoes as lava? When you purchase through links on our site, we may earn an affiliate commission. Here’s how it ...

The ocean on Ganymede may have more water than all the water on Earth. In this artist’s concept, the moon Ganymede orbits the giant planet Jupiter. NASA’s Hubble Space Telescope observed aurorae on ...

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 ...