What is the Galilean Moon Ganymede?

Ganymede is one of the Galilean moons of Jupiter discovered by Galileo Galilei in 1610. It is the largest of Jupiter’s moons and the largest moon in our solar system. It is the only moon known to have its own magnetic field.

Ganymede is a Galilean moon of Jupiter. The moon was discovered along with Callisto, Io, and Europa in 1610 by Galileo Galilei. His discovery of these four moons changed they way we think about the structure of our solar system. The provided evidence refuted the geocentric model and supported the heliocentric model.

Ganymede is the largest and most massive moon in our solar system. It is larger than the planet Mercury and the dwarf planet Pluto. Like all the other Galilean moons, Ganymede was a lover of Zeus in Greek mythology.

Ganymede is thought to be a moon made of mostly rock and water ice. It is the only moon known to have a permanent magnetic field, thought to be caused by Ganymede’s metallic core. Like Earth, this core is likely made of iron and nickel. The moon’s structure is differentiated meaning there are layers of different materials under its surface. Observations of the moon by the Hubble space telescope have indicated that Ganymede has a thin atmosphere mainly composed of oxygen.

There have been several missions to Ganymede. The first was Pioneer 10 which launched in 1972. The mission was sent to explore the planet Jupiter and its four Galilean moons. Pioneer 10 made a flyby on December 3, 1973. Later the Voyager 1 mission followed to study Jupiter and Saturn. Voyager made a closer approach than Pioneer, allowing for images of greater resolution to be taken.

Ganymede Facts