Following the first part of our etymological voyage through the Solar System yesterday, we're continuing our trip through the remaining planets.
The fourth planet from the sun and our best hope for survival after we've destroyed our current planet. Mars is named after the Roman god of war and protector of agriculture. Though Mars was based on the Greek god Ares, the more popular Latin name would make its way throughout history as the name of the planet. In many Romance languages such as French, Italian, and Spanish, Tuesday is Mars' day.
The largest planet in the Solar System takes its name from the king of the Roman gods. Iuppiter, as the Romans would have us spell it, was in charge of all the other gods and a sky god. The Romans considered him the equivalent to the Greek god Zeus.
Jupiter has four moons with interesting names. Though astronomers initally attempted to develop a nomenclature for the moons using Roman numerals by calling them Jupiter I, Jupiter II, Jupiter III, etc, they ended up preferring to name them all after lovers of the Greek god Zeus.
Europa was a woman who would later become the Queen of Crete, Callisto was a nymph and Io was priestess who fell in love with Zeus.
Jupiter's largest moon, Ganymede, which is larger than both the Moon and Mercury, was named for the son of King Tros who was transported to heaven by Jupiter having taken on the form of an eagle. Ganymede is the only of Zeus' lovers to have not been female.
Saturn, or Saturnus in Latin, has both a planet and a day named after him. Saturn was the god of the Capitol, and some even considered Jupiter to be the son of Saturn.
The unfortunately named Uranus was originally called George's Star, or the Latin name Georgium Sidus after the then king of England, King George III. Several other names were proposed including Neptune, Neptune George III and Neptune Great Britain which were all ignored in favour of naming the planet after the Greek god Οὐρανός (Ouranus), adopting the Latin form, Uranus. We bet you didn't know that the Greeks worshipped Uranus!
Neptune's discoverer, Urbain le Verrier, wished to name the planet after himself. Janus, the two-faced Roman god who had the month of January named after him, and Oceanus, the personification of the World Ocean, a river that surrounded the entire world, were also considered. Both of these names were rejected in favour of the name Neptune, after the Roman god of the seas and brother to both Jupiter and Pluto.
Though no longer a planet, as much as we want it to be, Pluto is the last destination on our trip. Once the smallest planet, Pluto is now classified as a dwarf planet and is named after the Greek god of the underworld, Πλούτων (Ploutos). Pluto was sometimes Hades and sometimes used as a nicer version of Hades since the ancient Greeks weren't too fond of him.
If you're wondering about the very odd family ties amongst some of the gods, it should be noted that the Ancient Greeks and Romans would often share gods or even assume that Greek gods exerted their power over Greece whilst the Roman gods would exert their power over Rome.