How The Planets got their Names

Callum Ashley
12 min readJun 17, 2019

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And making them make more sense.

There are eight planets in our Solar System and one star, all of which are named after ancient deities, besides one — Earth. Its mostly clear why the inner planets (those within the asteroid belt), Jupiter and Saturn have these names, relating back to ancient beliefs of the astronomers of Rome. As of there ability to see these planets with the naked eye and notice whilst the stars moved around in the sky, the planets did not — thus they were proclaimed πλανήτης (planētēs), meaning “wanderer”, or planets (which were thought to be orbiting Earth at the time). Slightly further out, beyond the reaches of Saturn the two Ice Giants lay just out of sight from the Human eye; unknown by the ancients, they were discovered by the use of the telescope in the 18th and 19th century; these astronomers decided to continue this ancient tradition, naming the orbiting celestial bodies after other ancient deities. But why were they named that specifically and do the names still fit with the understanding of the planets today?

Simple diagram of the major planetary bodies of the Solar System.

Today the IAU, or International Astronomical Union are in charge of naming the Planets, but today mostly use there time to name comets, asteroids, and geological features on the surface of moons and planets. They decided when it was founded in 1919 to continue the tradition of naming these objects after ancient deities. ‘Recently’ (in astronomical terms), they’ve named only a few notable objects, among them Pluto (of which we’ll discuss later on), Ceres, Eris, Haumea and Makemake, the four largest dwarf planets in the solar system (of which will also be discussed later on).

We’ll start with the first planet of the Solar System at 57.91 million kilometers from the Sun — Mercury. As all of the inner planets, Mercury was ‘discovered’ as a planet by ancient Babylonian scholars, though down to the fact that the Romans had the most influential scholars and language, it was named after the messenger of the Gods. This fits very well for Mercury; the likely reason it was named after the God of messages and travel was due to how fast it moved across the sky. In modern times, backed with scientific data this is true, with its year being 88 earth days due to its extremely fast Orbit around the Sun as of the intense gravitational pull, thus earning its title as Mercury — the God of Messages and Travel, of which the planet certainly does a lot of.

In Mercury also being the only God able to enter and leave the underworld, it could fit in with the planets hellish cycle grazing the suns surface during its orbit, creating a temperature of over four — hundred degrees, which is closely likened to visiting Hell. No other Olympian relates particularly well to Mercury, though Apollo does by some means in being God of the Sun, though Mercury is more the Suns Victim than its God, so Roman scholars were arguably successful in there dubbing of the first planet in the Solar System — Mercury.

Literally to close for comfort.

Next up is Venus. As Goddess of beauty, there’s no wonder the Romans pronounced one of the brightest stars to the human eye with such a title. Although, beneath the surface of its red — brown atmosphere, the planet is a hell-scape. Temperatures of four hundred and fifty degrees, constant volcanic eruptions, immense pressure from a very dense atmosphere and of a make up of carbon and sulfur dioxide, makes the Planet seem like its far beyond that of beauty — much closer to the destructive ideals of war. Though much like the Planet, the Goddess holds an instinctively jealous and dangerous inside, often killing women who believe they are, or even actually were (even innocents) more beautiful than herself.

But, unseen by the Romans, the planet rotates anticlockwise compared to other planets that rotate clockwise. This could be seen as a trait of the God Mars, who often disagreed and went against the Gods due to his violent and warlike attitudes; with a warlike surface, the planet could be seen as better named as ‘Mars’. Though in being the only female named planet, the opposite rotation could be seen to symbolize this also, so generally, the Romans again, were successful, but to a lesser extent in naming the brightest Planet Venus — as its beautiful on the surface, but on the inside can be inhospitable to any contenders who attempt to rival her status.

The third planet in our solar system, is our own — Earth. Unlike the rest of the solar system, its not named after any particular Roman God, and in fact derives from the Germanic word ‘erde’, which anticlimactically translates into ‘ground.’ Though, the Greek/ Roman word for Earth does derive from the Mother of the Gods, and the literal personification of the land itself, Gaia, or Gaea; but she is already honored in being named after the super continent Pangaea, that existed 350 million years ago, which is fitting as this was the mother of today continents and landmasses. Renaming our planet Gaea, also probably wouldn’t work out as Earth is home to more than just land; it has oceans, life and even the odd Starbucks littered on its surface.

The Pangea subcontinent

As of all of its traits, it could literally be named after any ancient deity — Neptune for the sea, Vesta, Goddess of the harvest and the hearth, or Juno, the Goddess of love and marriage, and thus also life. Taking all this into consideration, and the fact that the names from the Planets originated from Earth, it would make sense to name our planet after the first of all ancient deities in Roman mythology — Chaos. And considering the state of our planet today, it would make even more sense. Though, because the planet doesn’t really fit into any category, leaving it named after the ground isn’t a bad thing — so the Earth can keep its name.

The furthermost terrestrial planet from the sun is Mars, a bright crimson, almost blood coloured star in the night sky; no wonder the Romans named it after one of there favorite Gods, with its red hue emitting the violent idea of war — therefore naming it after Mars, the God of war. Though, today we know that below the thinning atmosphere, the planet is cold barren wasteland, with a far calmer surface than Mercury, Venus or even Earth. Though, as its average temperature is around minus sixty three degrees, its not exactly something you could battle against, but as the atmosphere is 96% carbon dioxide, you’d probably suffocate before you’d freeze to death.

Charon would likely be a more accurate name; the cold, ‘undead’, skeleton that transfers souls to the underworld would share similarities with the planet, as like Charon, Mars was striped down of its body, becoming a skeleton like planet, losing its atmosphere, water and possibly its life, now only taking others to the underworld, living in a region between life and death. But as Charon isn’t quite a God, its fair to say, it would be disrespectful to rename it as lesser than the other planets. Though its crimson glow does represent the attributes of the God of War, its surface and what we know today doesn't really back up this up. But I suppose it’s right for the planet to keep its Godly name alongside the others of the Solar System.

Jupiter, featuring its great red spot region — its three times bigger than Earth!

Next up is king of the solar system — Jupiter, a gas giant that could fit all the planets inside of it with room to spare! Its size can be clearly seen as the personification of the King of the Gods, Jupiter (better known as Zeus in its Greek form). Down to the fact that Jupiter influenced the creation of the terrestrial planets of the inner solar system, just like the King of the Gods influenced the creation of his children, like Mars and Mercury, there’s really no better name to give this massive planet. The storm that’s been raging within its atmosphere for over thirty years and the extreme winds that dominates its atmosphere further links to the fact that Jupiter whilst King of the Gods is also the God of thunder, lightning and storms — its almost like the Romans knew just as much as today's scientists. Or maybe just a coincidence.

Its at least sixty seven plus moons further express its dominance in the solar system, and show the many servants the deity had, as well as many lovers and children. As many of these moons are named after titans, defeated by Jupiter, like Io, its right that they should orbit his planet. Jupiter is more or less the perfect name for the perfect personification of of the King of the Gods.

The sixth planet in the Solar System and the furthest known to the ancients, Saturn, also has close similarities to its deity. Saturn, the father of Jupiter, rightly orbits behind its more powerful son having been defeated by Jupiter in war and replacing his kingly status. Like the fifth planet, the sixth has many moons (62 and likely many more unaccountable ones), many of which are similarly named after his servants, the Titans; Tethys, Enceladus and Rhea are among many others.

Likely one of the most famous planets in the solar system, and not just for its rings, but also for the fact that, if there was an ocean big enough, it could float on water!

The seventh planet, renamed by classicists after it was briefly named ‘Georges Planet’ (for George III), Uranus, continued the tradition of naming the larger orbiting bodies of the sun after deities. Uranus was the father of Saturn, who was the father of Jupiter, so its only right to have Uranus behind his own, more powerful son, who also defeated him, taking his title, much like Jupiter to Saturn. In also being the literal personification of heaven in mythology, its wonderfully light bluish hue echoes this trait. The strange thing about Uranus, it that its rotation has been tilted to such an extent, it now rolls along its equator, with the north pole always facing the Sun, likely due to a collision with another planetary body. This mutilation similarly emphasises the mutilation of this deity by his son Saturn, who rather savagely cut off Uranus’ genitalia. So Uranus is a planet that fits its name particularly well, one that the Romans would have likely selected themselves.

Though, a planet that doesn’t really fit its name very well is Neptune; though its deep blue hue is reminiscent of an ocean (its surface may even contain water), considering the last three bodies all linked in via parenthood, ‘Neptune’ is kind of out of the blue(!) when it comes to its naming. Discovered about 60 years after Uranus, in 1846, Neptune was the last of the eight planets named.

Though, its possible that Neptune could be named Gaea, as the deity was the mother of Uranus, continuing the trend of parenthood, especially down to the fact that Neptune was discovered due to its gravity influencing the orbit of Uranus, but as the name derives from earth in Greek and Latin, and the fact Neptune is a frozen gas giant, it kind of negates this idea. Plus Gaea is taken by an ancient form of the Earth, and in a way also relates to our own planets name. So its probably a good idea just to keep Neptune as it is, with its ocean coloured atmosphere.

Arguably, Saturn could have been named Juno, after Jupiter’s wife and Uranus, Pluto, whilst Neptune could remain Neptune, all making sense, as they were the four most dominant Gods in the mythology and on Olympus, whilst there weaker counterparts, the titans would orbit them named as moons.

Both the Ice Giants are very similar sizes, though they dwarf earth in comparison

Lastly, and indeed least — Pluto. Though it isn’t deemed as a planet today, it was when it was given its name, the Roman God of the underworld. This name is particularly fitting for this body, as like its counterpart, the God of the underworld, Pluto's orbit crosses the path of Neptune's, and so for just over half of its orbital period its the 8th ‘planet’ in the solar system, representing both the Gods limited affairs upon Olympus, as well as the Gods battle with Neptune to be the second most powerful God, after Jupiter. Down to the fact that Pluto was not one of the twelve Olympians and in fact opted out of the Gods affairs, also surprisingly links to the fact that scientists denounced its status as a planet to become a dwarf planet. Even though Astronomers consulted the Classicists before naming the planet, it fits extremely metaphorically well, despite them not having the scientific information and reasoning that we have today.

Though, it would be a shame to miss out of the other dwarf planets of the solar system. Firstly the second largest dwarf planet, Eris, was named after the Greek version of her name rather than her Roman form. As God of strife and disagreement, her Roman form would have been ‘Discordia’; though I think the Greek version has a far better ring to it. This name fits well, as when it was discovered there were the debates whether to pronounce it as a planet (it lies between Mars and Jupiter as the largest object in asteroid belt) or for it to be a ‘dwarf planet’. At the time there were also debates over the issue of Pluto's planetary status, and Eris’s discovery certainly didn’t help, adding to the disagreements and strife, much like its equivalent deity would have done.

An interesting diagram of all the known major dwarf planets in the Kuiper belt; there all about the size of Earths core.

Ceres is another dwarf planet discovered around the same time and thousands more in the Kuiper Belt; down to the fact that Ceres is one of thousands of Roman Gods of agriculture, it fits as of the thousands of other dwarfish planetary objects (which also happened, like Eris to degrade Pluto’s status). Strangely there are two other major dwarf planets that are not named after Roman or Greek deities — but from the polytheist regions of various Pacific tribes.

Haumea is named after the Hawaiian God of fertility and childbirth; ironically this works well as it was one of the first dwarf planets discovered in the Kuiper Belt in 2004 at a time when thousands of others alike were also discovered, like Makemake, another God of fertility but from the people of the Rapa Nui people on Easter Island. As both of these planets were discovered on the Hawaiian and Easter Islands, I suppose its only right to name them after the previous deities of there areas. Though, if they were to continue the tradition of Roman or Greek deities, its likely like Ceres, they would have been named after various Gods of agriculture. But also, down to the fact that there in a relatively newly discovered region of the solar system, its right to name them after deities of other regions, and also to remember them as well as the Romans and the Greeks, who for so many years have have been in the spotlight when it come to planetary naming.

Planet Nines ridiculously large orbit around our star.

In a rough summary, the planets names mostly link with the scientific data and obvious observations made; the Romans were even more or less perfect in there overall naming of the planets with links to there Gods, which astronomers also continued pretty accurately too. But what if the speculated Planet Nine exists? Well, thanks to the hundreds of Gods in Roman Mythology, there are almost endless names to choose from; though, so far Planet Nine has been called ‘Donald Duck’ and even just ‘Planet Nine’, so really not much thought has gone into it. But naming it after a deity would continue a tradition over 2000 years old, so it would be right to name the last discovered major planet after the last of the twelve Olympians to join Olympus — Bacchus. With Bacchus being the God of Wine and alcohol, the planets, projected, strangely shaped and massive orbital period of 20,000 years could go further to show the deities drunk qualities, mirroring that of the planets!

Ultimately, the solar system is a large and largely unexplored region that the Earth has given names to based on some qualities of some ancient made up deities — at the end of the day the names don’t really matter, though they are better than simply ‘Planet Nine’ or a number. But as the universe is so vast, if were ever to explore its vast reaches then we would probably run out of deities to name other objects with, but for the time being the solar systems planets and there related deities should stay.

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Callum Ashley

Mainly Planetary science, theories and a bit of philosophy.