Jupiter’s Moon Ganymede
The largest satellite in the Solar System, Jupiter’s moon Ganymede, looks remarkably like a giant version of the Moon. Yet this apparently lifeless body holds a curious feature that has scientists stumped because by rights it should not exist.
Jupiter’s moon Ganymede, the Solar System’s largest moon at 5,200 km (3,300 miles) in width is twice as large as the Moon and much more mysterious. Orbiting Jupiter at roughly one million kilometres (625,000 miles) it takes the satellite just seven days (Earth-days) to make a complete circle around the planet.
The crust of Ganymede is composed of ice water. The mantle is believed to be divided into two sections. The outer layer is thought to be a warm ice layer while the inner mantle consists of silicate rock. At the heart of the moon partially molten iron and iron sulfide exist in the core.
Jupiter’s Moon Ganymede: Much More Than Meets The Eye
The most startling aspect of Jupiter’s moon Ganymede is the false illusion its seemingly ordinary appearance commands. The differing shades of grey suggest little of the oddness that lurks underneath. One of the first glimpses into this rests with its terrain.
The surface is marked by unusual variants. There are two different textures and colours on the moon, rougher and darker and smoother and lighter.
The lighter shades of grey are much newer and less heavily cratered than the dark areas. This suggests that the surface of Ganymede has undergone relatively recent resurfacing. Scientists believe that plate tectonics are responsible for this.
But Jupiter’s moon Ganymede shouldn’t have plate tectonics, although it is the largest moon in the Solar System, it is still far too small to have a molten core.
An Ocean Of Saltwater?
Below Ganymede’s crust is assumed to be a liquid ocean of saltwater. Heated up by the hot core and the incredible effects of Jupiter’s powerful gravitational field, it resides between layers of ice. If this ocean of water has existed for a long enough period, there may be the possibility of life on Jupiter’s moon Ganymede.
The Magnetosphere That Shouldn’t Be
The saltwater ocean and the plate tectonics of Ganymede are not the only odd things about the moon. This world is the sole satellite in the Solar System that has a magnetosphere. This is made possible by the partially molten core of iron. The magnetosphere also means that Ganymede has aurora.
Highly Recommended Reading
Check out Yellow Magpie’s Jupiter: The Local Gas Giant Of The Solar System for more insight into the largest planet in the Solar System and The Moons Of Jupiter: The Solar System Within The Solar System for more detail on Jupiter’s moons.
You may also wish to take a gander at The Solar System And Beyond: A Guide To The Cosmos.
Cosmos is a highly recommended book. It contains large, full-page pictures of the asteroids and writing on the subject by the highly competent author, Giles Sparrow.
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