A moon can sit next door to another and still feel like a different world. Around Jupiter, that contrast shows up fast. Io ...

While Io, the most volcanically active moon in the solar system, appears completely dry and devoid of water ice, its neighbor Europa is thought to harbor a vast global ocean of liquid water beneath ...

A comet from another star system will swing by Mars on Friday as a fleet of spacecraft trains its sights on the interstellar visitor. We already know a decent amount about how planets form, but moon ...

Astronomers have found 12 more moons orbiting the planet Jupiter. These moons are all small — just 5 kilometers or less across — and one of... Galileo Would Be Stunned: Jupiter Now Has 79 Moons More ...

A new international study co-led by Aix-Marseille University and Southwest Research Institute (SwRI) reveals that the striking contrast in the water contents of Jupiter’s Galilean moons was ...