Ganymede: The Largest Moon Once Thought To Have More Water Than Earth And Have Life

Ganymede is the largest moon in the solar system and the biggest moon of the gas giant planet Jupiter. So, what does it look like and how big is it?

Ganymede: The Largest Moon: https://t.co/MpArjry1tH by NASA, JPL, Galileo Probe pic.twitter.com/8MdhaoZVO2

— Astro Pic Of The Day (@apod) May 14, 2017

NASA reports that Ganymede is bigger than the planets Mercury and Pluto. It features the icy surface that is dotted with young craters that are overlying a mixture of older and darker cratered terrain with ridges and grooves. It has a big round feature on the upper right referred to as "Galileo Regio."

Jupiter & moons seen from London - (1)15th May compared to (2)10th of May #Jupiter #Europa #Callisto #Io #Ganymede @EpicCosmos pic.twitter.com/upHtgOP1BC — Ian Wilson (@iewilson) May 14, 2017

This largest moon was once thought to have an ocean layer that has more water than Earth. It is also speculated that it might contain life, as pointed out by Space Fellowship.

The surface of Ganymede has two main types, namely the dark regions and the lighter regions. The dark regions cover about a third of the satellite. It is saturated with impact craters and dated to 4 billion years ago. Meanwhile, the lighter regions cover the remainder. It is crosscut by intense ridges and grooves and slight less ancient. The moon comprises of silicate and water ice.

Ganymede is the ninth biggest object in the solar system. It is estimated to have a diameter of about 5,268 kilometers (10,273 miles). It is also the only moon that has a magnetic field and to have the lowest moment of inertia factor. It contains metallic core, too.

This biggest moon was first discovered and observed by Galileo Galilei on Jan. 7, 1610. It was named after the mythological Ganymede, the cupbearer of the Greek gods and Zeus' lover, which was suggested by the astronomer Simon Marius.