The journal
Open the journal →The conversation starts in the journal — be the first to post.
About Io
Io is the innermost and second smallest of the four Galilean moons of Jupiter. Slightly larger than Earth's Moon, Io is the fourth-largest natural satellite in the Solar System, has the highest density and strongest surface gravity of any natural satellite, and the lowest amount of water by atomic ratio of any known astronomical object in the Solar System.
Everything about Io →