Ganymede, The Largest Moon In Our Solar System
Did you know that the largest moon in our Solar System orbits the largest planet in our Solar System? Ganymede, a moon orbiting Jupiter wins the prize as the largest moon in our Solar System.
Ganymede holds the position as the seventh moon outward from the surface of Jupiter. It has a diameter of 3,270 miles. For comparison, Earth’s moon is 2,159 miles in diameter. If you want to compare Ganymede to a planet, it is 8% bigger than the planet Mercury! The next biggest moon in the Solar System happens to orbit the planet Saturn. It is called Titan. You would think the biggest moon would be called Titan – not Ganymede - wouldn’t you?
The four biggest moons orbiting Jupiter – Ganymede, Callisto, Io, and Europa – are called Galilean Satellites. They are named after Galileo Galilei who discovered them in 1610 through a homemade telescope.
Ganymede is made of equal amounts of silicate rock and water ice. It is thought to have a liquid core with a saltwater ocean laying nearly 200 km below it’s icy surface. It’s surface is quite unusual, having dark regions loaded with impact craters and wide expanses of light regions that have pronounced groves and ridges. It is generally thought that these areas have been created by tidal heating of ice below the surface.
Another unique thing about Ganymede is that it is the only moon in the Solar System known to have a magnetosphere, which is probably being generated by it’s liquid iron core. It also has a thin oxygen atmosphere.
The first man-made spacecraft to visit Ganymede was Pioneer 10. It flew by the giant moon on December 3, 1973.