Ganymede

==Overview==
Ganymede (Jupiter III) is Jupiter's largest moon, and the largest moon in the Solar system overall, bigger than the planet Mercury. It is the seventh moon by distance from Jupiter, and the third Galilean moon. It is also the only moon to have a magnetic field. Discovered by Galileo Galilei in 1610 it was, like the other Galilean moons, originally thought to have been a star.This article has been adapted from the Space Engine ingame wiki
==Surface environment==
The surface of Ganymede can be divided into the old dark regions and relatively younger and lighter regions. Although both have craters, the dark regions appear to have a much more extensive amount than the lighter regions. Most of these craters are thought to have formed around 3.5-4 billion years ago during a period of heavy cratering. The surface of Ganymede also contains a large amount of grooves and ridges, whose formation is currently not completely understood, although are generally thought to be tectonic origin.
==Internal structure==
The Ganymedian crust, along with the outer mantle, is composed mainly of ice, while the inner mantle is composed of silicates. Ganymede has a liquid iron core, confirmed by the presence of a magnetic field around the planet. The core is thought to be around 700-900 km in diameter, while the icy mantle is around 800-1000 km.
==Atmosphere==
Essentially vacuum, Ganymede has an extremely tedious atmosphere with an atmospheric pressure of around 1 μPa. The little atmosphere it has is thought to be composed mainly of molecular oxygen.
==Exploration==
The first probes to attempt to collect data about the satellite were Pioneer 10 and Pioneer 11 in the 1970's. The Voyager spacecraft were the ones to determine that Ganymede was larger than Titan, previously thought to have been bigger and to detect the grooved terrain. The Galileo spacecraft was the one that made the closest contact with the moon, passing just 264 km above it's surface. Recently, New Horizons passed by Ganymede in 2007 on its way to Pluto, making topography and composition maps while passing by.
==Images==
File:Ganymede-001.jpg
File:Ganymede-002.jpg
File:Ganymede-003.jpg
File:Ganymede-004.jpg
File:Ganymede-005.jpg
File:Ganymede-006.jpg
Category:Real objects
Category:Moons
Category:Objects
Category:Solar System
Category:Aquaria