There are 288 discovered natural satellites – or moons, as they are colloquially known – in the Solar system. Most of these are found in the outer gas giants. However, many of these have not received proper names as they were discovered recently and have yet to be confirmed. Only 164 moons have proper names.
Out of those, there are 7 moons whose names start with the letter G. These are all listed in the following table. Below you will also find some additional details about each, including physical characteristics, the original meaning of their names, etc.
| Moon Name | Planet | Name Meaning |
|---|---|---|
| Galatea | Neptune | One of the Nereids in Greek mythology |
| Ganymede | Jupiter | Male hero of Troy. Served as Zeus cup-bearer in Olympus |
| Geirrod | Saturn | A Jötunn (giant) who was killed by Thor |
| Gerd | Saturn | Wife of the god Freyr |
| Greip | Saturn | A female Jötunn (giant) |
| Gridr | Saturn | A female Jötunn (giant) |
| Gunnlod | Saturn | A female Jötunn (giant) |
Galatea
Galatea was discovered in 1989 during the Voyager 2 flyby of Neptune. Named after one of the fifty Nereids (sea nymphs) from Greek mythology, this small inner moon is approximately 88 kilometers in diameter. It orbits Neptune at about 62,000 kilometers from the planet’s center, within Neptune’s ring system. Galatea helps shepherd Neptune’s Adams ring, much like similar moons of Saturn help maintain that planet’s rings. It completes one orbit around Neptune in just 10.3 hours.
Ganymede
Discovered by Galileo Galilei in 1610, Ganymede is the largest moon in our solar system, even bigger than the planet Mercury, with a diameter of 5,268 kilometers. Named after a Trojan prince in Greek mythology who was carried to Olympus by Zeus to serve as cupbearer to the gods, Ganymede is one of Jupiter’s four Galilean moons. It is the only moon known to have its own magnetic field and is believed to have a subsurface ocean containing more water than all of Earth’s oceans combined. Its surface features both ancient dark regions and younger, grooved terrain.
Geirrod
Discovered in 2004 by Scott S. Sheppard and his team, Geirrod is one of Saturn’s irregular satellites. Named after a jötunn (giant) from Norse mythology who was famously killed by Thor after trying to trick and kill him, this small moon is approximately 4 kilometers in diameter. It follows a retrograde orbit at an average distance of 21.9 million kilometers from Saturn, suggesting it might be a captured object rather than having formed alongside the planet.
Gerd
Discovered in 2004 by Scott S. Sheppard’s team, Gerd is one of Saturn’s irregular satellites. Named after the beautiful frost giantess from Norse mythology who became the wife of the god Freyr, this moon is approximately 3 kilometers in diameter. It orbits Saturn at an average distance of 20.8 million kilometers. Like many of Saturn’s irregular satellites, its surface is quite dark, suggesting a possible asteroidal origin.
Greip
Greip is one of Saturn’s irregular satellites, discovered in 2006 by Scott S. Sheppard and his team. Named after a female jötunn (giant) from Norse mythology who was the daughter of the giant Geirröðr, this small moon is roughly 3 kilometers in diameter. It follows a retrograde orbit at an average distance of 18.4 million kilometers from Saturn. Its orbital characteristics suggest it was likely captured by Saturn’s gravity rather than forming in place.
Gridr
Discovered in 2004 by Scott S. Sheppard and his team, Gridr is one of Saturn’s irregular satellites. Named after a female jötunn (giant) from Norse mythology who helped Thor by giving him a magical staff and belt of strength, this moon is approximately 4 kilometers in diameter. It orbits Saturn at an average distance of 19.4 million kilometers in a retrograde direction, typical of captured irregular satellites.
Gunnlod
Gunnlod is one of Saturn’s irregular satellites, discovered in 2004 by Scott S. Sheppard’s team. Named after the female jötunn (giant) who was the guardian of the mead of poetry in Norse mythology, this small moon is approximately 4 kilometers in diameter. It follows a retrograde orbit at an average distance of 21.2 million kilometers from Saturn. Like many of Saturn’s irregular satellites, its dark surface and orbital characteristics suggest it was captured from elsewhere in the solar system.
Click on a letter below for a list of moons that begin with it.
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z
Related:
For more on how moons are named check out this article.