Their relationship was a royal scandal, he was a servant
All planet names are governed by a group called the International Astronomical Union. When the IAU was formed back in 1919, they recognized that most of the planets (with the exception of Uranus, Neptune, and Pluto), already had names from the Classical period, so continued that tradition in naming new planets.
Mercury is the closest planet to the Sun, and the fastest – it moves once around the Sun every 88 Earth days.
Mercury is also the name of the swiftest Roman god – he is the patron god of commerce, communication, eloquence, travelers, trickery, and thieves.
Next out from the Sun is Venus, the brightest natural object (besides the Moon) in the night’s sky.
This planet is named for Venus, Roman goddess of Love. She also presided over beauty, sex, fertility, and prosperity. According to Roman myth, she was the ancestor of the Roman people through her Trojan son Aeneas. In addition, Julius Caesar claimed to be a descendant of Venus.
Fourth from the Sun is Mars – the Red Planet. This planet orbits once every 687 Earth days with its two moons – Phobos and Deimos.
In Roman myth, Mars is the god of war. Unlike the Greek god of war, Mars was one of the most powerful and important gods, second only to Jupiter. However, in the Greek mythology, Mars (Ares) is often accompanied by twin brothers Phobos and Deimos, the personifications of fear and terror.
Jupiter is the largest planet in the solar system, with a mass two and a half times greater than all the other planets combined. A fast-swirling gas giant, Jupiter’s surface is covered with storms, including the famous (and now shrinking) Great Red Spot.
In mythology, Jupiter is king among the gods. Wielding his lightning bolt, he presides over every natural force, with the ability even to grant immortality.
Saturn is sixth out from the Sun, and the second-largest in the Solar system. It’s the planet with the largest and most visible rings around it (although not the only one – Jupiter and Uranus also have rings).
In myth, Saturn is a very old god – the first of Rome. He was principally a god of agriculture, renewal, and wealth, although he later became a god of time. The temple of Saturn in Rome housed the state treasury and has his own holiday in December – Saturnalia.
Seventh from the Sun, Uranus is so far out that it is no longer referred to as a “gas giant” – rather, scientist increasingly calls it an “ice giant.” It has the coldest atmosphere of any planet at a maximum of 49 degrees Kelvin (-371.47 degrees Fahrenheit).
Uranus is a bit odd – it is the only planet named for a (solely) Greek god. Uranus was the god of the sky, the father of the Titans, and husband (and because the Greeks were kind of cool with godly incest, also son of) Gaia, the Earth. This makes him both grandfather and uncle to the Olympian gods.
Neptune is the farthest official planet in the solar system. This blue planet joins Uranus in the “ice giant” category and was the only planet to found by mathematical prediction rather than observation.
The Roman Neptune is the powerful god of the sea. He was the brother of Jupiter and Pluto, and even had his own celebration at the height of summer, on July 23 – the Neptunalia. Interestingly, Neptune was also seen as the god of horses.
While Pluto is technically designated a “dwarf planet,” it was named as a planet, and long held as one until the new definition of “planet” was made in 2006. Pluto was the farthest planet in the solar system – so distant that light from the Sun takes about 5.5 hours to reach it, although due to its elliptical orbit, it could arrive faster or slower. It has five known moons – Charon, Nix, Hydra, Kerberos, and Styx.
In Roman (and Greek) myth, Pluto was the ruler of the Underworld. The names of the moons all come from Greek myth, however – Styx is the name of the river that forms the boundary between Earth and the Underworld; Charon is the ferryman who carries souls of the dead across the Styx; Nix is the personification of the night; the Hydra was a poisonous multi-headed monster killed by Hercules; and Kerberos is the name of the three-headed dog that guarded the Underworld.