Galileo's Ganymede

Ganymede the largest moon of Jupiter and the wider solar system was discovered by Galileo Galilei on January 7, 1610, also the first moon aside from our moon was discovered.   

Ganymede is a name from Greek mythology and is the name of a young prince of Troy who was carried away by Zeus (Jupiter in Roman mythology) to serve as a cupbearer for the gods because of his magnificent beauty. 

Notable info

• Formed approx 4.5 billion yrs ago
• Radius:  1,635 m/2,631 km  
• Third farthest satellite from Jupiter (665,000 m/ 1.07 mil km )
• Bigger than Mercury and Pluto
• 9th largest object in the Solar System
• One day is an Earth week & one year is 12 Earth Years

Structure

Ganymede has a metallic iron core surrounded by a spherical shell of ice and the solid surface, underneath the ice is very lumpy from either rock formations or other tectonic activity.  this structure can be compared to a club sandwich and was suspected of having underground oceans from the 1970s. Ganymede also has the unique property for a moon of a magnetic field, discovered by the Galileo spacecraft in 1996.

Pop Culture

• Cowboy Bebop
• British Series: Red Dwarf
• 3001: The Final Odyssey - Ganymede City

Exploration

• Pioneer 10 (1973)
• Pioneer 11 (1974)
• The Voyagers (1973 & 1979)
• Galileo : 6 flybys (1996 - 2000)
• New Horizons (2007)
• Juno (Christmas 2019 & June 2021)
• Jupiter Icy Moon Explorer (JUICE) : 2031 - ?