How Did the Planets Get Their Names? Planet Name Origins

(Last Updated On: June 7, 2021)

You might not think about the planets very often, but you are probably aware that they’re all named after some very significant figures in the Roman mythos. But you might be wondering how we came up with all those names, because there’s no way we just picked a bunch of gods out of a hat and called it a day, right? Right? Anyway, here are some planet name origins.


The first five planets (excluding Earth) were documented by the Romans–and they don’t really have a “point of discovery” as a result. People just knew they existed because they, along with the Sun, were among the brightest objects in the sky. Plus, they were visible to the naked eye without things like telescopes.

So Mercury. He’s one of the twelve “Dii consentes” in the pantheon–which really just means he’s one of the major gods. He’s the god of commerce–but more relevant to the planet he’s also a messenger. Mercury is a speedy god. It’s only fitting that the planet that moves the fastest around the Sun would receive that name. It only takes 88 days (in terms of Earth, so 24 hours) for Mercury to complete a full orbit around the Sun. 


The Birth of Venus, Sandro Botticelli, c. 1484-1486

Venus is the third brightest object in the sky–after the Sun and the Moon. When the Babylonians were looking at the sky, they called Venus Ishtar–who is a deity also associated with love and beauty (but also war). It’s Venus’ brightness that probably earned it its name back when people were just looking at the sky.


The name “Earth” is derived from the English and German roughly translating to “ground.” This makes Earth the only planet not named after Greco-Roman mythology. In other languages the name “Earth” is still often derived from words for soil and ground. 


Mars is easy, named after the god of war. It was red in the sky, sharing its color with blood. Bam, slam, welcome to the jam, the red dot in the sky was named after bloodshed.

The Romans weren’t the only ones who made that conclusion either. In Egypt they called it “the red one.” 


Jupiter is also quite easy–it’s the biggest one. In the pantheon, Jupiter is the king of the gods. You might know him as the sky god, or the god of thunder. 

But here’s the fun facts part. You might also know Jupiter for being unable to keep it in his pants–he had a lot of lovers. The first four moons discovered by Galileo Galilei were named Io, Ganymede, Europa, and Calisto. They’re some of his most well-known affairs. As we kept discovering more of Jupiter’s moons, we kept naming them after his affairs. Once we ran out in around 2004, we started naming the moons after the children born to Jupiter’s affairs. Of which there are many.

Eventually, NASA would send a spacecraft to Jupiter in the name of science. This mission would launch in 2011, and is set to conclude in July of 2021. If you know where this is going, you know this is the punchline to a joke that started when Jupiter’s moons were discovered over 400 years ago. The mission to examine Jupiter is named Juno. 

Juno is Jupiter’s wife


Also Saturn is known for eating his kids. Patricide is a big thing in the Greco-Roman mythos.

Saturn is the last planet visible in the sky without any kind of aid, and named after the Roman god for agriculture–introducing agriculture to the people. The Greek equivalent to Saturn is Kronos–and both govern time (as well as the harvest we just established). 

In ancient Greek Saturn was also referred to as Phainon, and the Romans called the planet the Star of Saturn. 


Now we’re at the first planet we actually have a record of some dude with a telescope discovering. Uranus’ discovery is credited to William Herschel in 1781. Though it has been recorded as a star well, well before Herschel noted it as a planet. He first noted it as a comet too, though other astronomers round the world started calculating Uranus’ orbit–confirming its status as a planet. 

Keeping in tradition (except for Earth), Uranus is named after a Greco-Roman deity of the same name. This time he’s Greek, and Uranus (sometimes Ouranos) is considered one of the really old primordial gods. He predates the Greco-Roman gods you’re probably familiar with, and is husband to Gaia–Mother Earth. 

Honestly, it’s even more confusing, because Uranus is the only planet named after a Greek deity, rather than their Roman counterpart (which would be Caelus in this case). 

Uranus’ name wouldn’t be locked in until almost 70 years after its discovery, proposed in a 1782 treatise by Johann Elert Bode. He was one of the key figures in determining the planet’s orbit. Why did he propose Uranus? His logic was quite simple, Saturn is Jupiter’s dad, so it makes sense for Uranus to be Saturn’s dad. 


So obviously, Neptune has to be Uranus’ dad, right? 

Wrong, Neptune is the Roman god of the sea. While Galileo recorded Neptune as a star, we wouldn’t start figuring out it was a planet until the 1840s. The name Neptune became accepted late into 1846 due to its blue color. 

Here’s a fun fact. French astronomer Urbain Le Verrier tried to name Neptune after himself. People didn’t like it, since it went against the tradition of naming planets after Greco-Roman deities. 


Yeah, Pluto’s status as a planet is often debated. Even in 2021. But it’s named after the Roman god of mortality, while also literally translating to “the wealthy one.” In Greek, Pluto is Hades, the god of the Underworld.

The name Pluto was proposed by Venetia Burney in 1929, when she was 11. 

Other suggestions for Pluto’s name at the time included Zeus (we already had Jupiter), Percival, Constance, Cronus (we already had Saturn, and also it was proposed by a wildly unpopular guy), and Minerva. 

Pluto received a unanimous vote for its name by the Lowell Observatory

See if you know other Greco-Roman creatures here.

About the Author:

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Kyler is a content writer at Sporcle living in Seattle, and is currently studying at the University of Washington School of Law. He's been writing for Sporcle since 2019; sometimes the blog is an excellent platform to answer random personal questions he has about the world. Most of his free time is spent drinking black coffee like water.