Sign up for free

Newsletters

Once a month
get new photos
and expert tips.

Science and Space
Main Health and Human Body Earth Space Prehistoric World A-Z

Jupiter and Its Moons

Photo: Jupiter and its four largest moons

This family portrait, a composite of the Jovian system, includes the edge of Jupiter (with the Great Red Spot visible) and Jupiter's four largest moons, known as the Galilean satellites. From top to bottom are Io, Europa, Ganymede, and Callisto. The smallest of these four moons, Europa is about the size of Earth's moon.

Photograph courtesy NASA