Ganymede

Ganymede is the the largest satellite in the solar system and the largest moon around Jupiter. It has a diameter of 5262 km and, if it was orbiting around the Sun, it would be considered a planet. Ganymede has no known atmosphere although small amounts of ozone have been detected, hinting at a small oxygen atmosphere.



Ganymede has a strange geological history. It contains mountains and valleys and lava flows. It has both light and dark areas as shown by the picture above, each having different geological structures.

References

See Moons Of Jupiter