Random Moon Name Generator

What the random moon name generator does

These are not invented names. Every one is a real moon, a real object orbiting a real world in this solar system, from our own single Moon out to the tiny frozen companions of dwarf planets past Neptune.

Press the button and you get one, with the world it orbits.

And hidden in the list is one of the loveliest facts in astronomy: one planet in this solar system does not name its moons after gods. It names them after characters from plays.

How to use it

1. Choose how many you want. One if you are deciding, a batch if you are browsing.
2. Press Generate. A fresh draw every time.
3. Press Copy to take the set with you.

The planet whose moons come from a playwright

Look through the list for Miranda, Ariel, Umbriel, Titania and Oberon. Every one of them orbits Uranus. And every one of them is a character from English literature rather than a figure from myth.

This does not happen anywhere else. The moons of Jupiter are named for the lovers and children of Zeus. The moons of Saturn are Titans and giants. Mars has Phobos and Deimos, fear and dread, the horses that pulled the war god's chariot. Everywhere you look in the sky, the names come out of ancient mythology, because that is the rule the whole of astronomy has followed for as long as there has been astronomy.

Uranus breaks it. Titania and Oberon are the queen and king of the fairies from A Midsummer Night's Dream. Miranda and Ariel come from The Tempest. And of the twenty-odd moons Uranus has, almost every single one is a Shakespearean character, with a handful borrowed from a poem by Alexander Pope.

How this happened is a small chain of accidents. William Herschel discovered Uranus in 1781, the first planet ever found with a telescope, and then found its two largest moons in 1787. He did not name them. For decades they had no names at all, because naming the moons of a planet was not yet an established thing to do. When two more turned up in 1851, there were four nameless moons and the confusion had become unworkable.

The job of naming them fell to John Herschel, William's son, himself a formidable astronomer. And for reasons nobody has ever fully pinned down, he did not reach for the usual gods. He reached for the two largest, already informally linked to the fairy king and queen, and made the whole system literary. Titania, Oberon, and then Ariel and Umbriel from Pope. The precedent was set, and every astronomer who has found a moon of Uranus since has kept faith with it, all the way to discoveries made in the last few years that are still waiting for their Shakespearean names.

So there is a planet named after a Greek sky god, the one genuine exception among planets that otherwise carry Roman names, and it is circled by a court of fairies and spirits and shipwrecked dukes. The oddest planet in the solar system keeps the oddest company, and it does it on purpose.

Every planet keeps a different guest list

Once you know the moons are named to themes, the whole solar system turns into a set of rooms, each with its own rule about who is allowed in.

Jupiter, the king of the Roman gods, takes his moons from the loves and offspring of his Greek self, Zeus. Io, Europa, Ganymede, Callisto: every one of them a figure from the tangle of myths around that god. It is thematically tidy in a way that is almost funny, an entire orbiting family of a god's romantic history.

Saturn takes Titans and other giants of myth, the older generation of gods, which suits a planet named for Jupiter's father. Neptune, god of the sea, takes water gods and sea spirits, which is why its great moon is Triton, son of the sea.

And out past Neptune the rule changes again, to fit the places. Pluto and its moons draw on the underworld, because Pluto is its god: Charon, the ferryman of the dead, and Styx and Kerberos, the river and the guard dog of the land beyond it. Then the newer dwarf planets reach into other mythologies entirely. The moons of Haumea, named for a Hawaiian goddess, are her daughters, Hiʻiaka and Namaka. The rule is no longer just Greek and Roman. It has started to admit the myths of the whole world.

None of this is casual. There is a body, the International Astronomical Union, that decides these names, and each family of worlds has an agreed theme that any new name has to fit. Discover a moon of Saturn and you may not call it whatever you like. It has to be a giant. The sky is themed, and the themes are enforced.

Who gets to name a world

For most of history the answer was simple: whoever found it. Discover a moon, name a moon. That is how the early moons got their names, and it is why so much depended on the taste of individual astronomers like John Herschel, who could quietly decide that an entire planet would speak Shakespeare.

That freedom did not last, and it is worth understanding why it ended, because the reason is not bureaucratic fussiness.

As telescopes improved, discoveries multiplied, and the old free-for-all started to produce chaos. The same object would end up with different names in different countries. Numbering schemes contradicted each other. For a while the moons of Uranus were labelled in one order by Herschel and the opposite order by others, and publications simply had to pick a side. When a thing has two names, it effectively has none, because no two people can be sure they are talking about the same object.

So the naming was handed to a single authority, the International Astronomical Union, founded in 1919, and now every official name for every object in the sky passes through it. This is the same body that drew the formal boundaries of the constellations, and the same body whose ruling on what counts as a planet famously cost Pluto its status. It exists so that the sky has exactly one agreed name for each thing, which sounds like a small ambition until you remember what the alternative looks like.

The freedom of the individual discoverer has narrowed to a proposal, submitted and approved, made to fit the theme of the world in question. What has been kept, deliberately, is the poetry. The Union could have switched to catalogue numbers and never argued about a name again. Instead the newest moon of Uranus, found only recently, will in time be given the name of some character out of Shakespeare, because a rule made by one astronomer's whim in 1852 turned out to be worth protecting.

Where these come from

The moons are drawn from a list our team researched and checked by hand, each paired with the world it orbits, so these are real satellites rather than invented names. Your browser picks from them at random. Nothing you do here leaves your device.

Questions people ask

Why exactly did Uranus get Shakespearean moons?

The honest answer is that nobody is completely sure. John Herschel chose the first literary names in 1852, starting from the fairy king and queen for the two largest moons, and later astronomers kept the tradition going. Why he broke with mythology in the first place was never fully recorded, which leaves the single strangest naming decision in the solar system as a bit of a mystery.

Which planet has the most moons?

This keeps changing, which is part of the fun. For a long time Jupiter held the record, then Saturn overtook it as surveys turned up dozens of small, distant moons, and the count is still climbing on both. Any specific number you are given is a snapshot, and it will be out of date soon, because the small ones are still being found.

Why is our Moon just called "the Moon"?

Because it was the only one anybody knew about for almost all of human history, so it never needed a distinguishing name. It was the Moon, the way the Sun is the Sun. Its more formal name, Luna, only really gets used when someone needs to speak about it as one moon among many, which is a genuinely recent problem.

What actually counts as a moon?

Simply a natural object in orbit around a planet or other body rather than around the Sun directly. There is no lower size limit, which is exactly why the counts keep climbing: as instruments improve, smaller and smaller chunks of rock and ice qualify, and each planet's tally grows without the definition changing at all.

Can I name a moon after myself?

No, and pointedly so. Official names go through the International Astronomical Union and must fit the established theme for that world, and naming an object after yourself is not permitted. Anyone offering to sell you the rights to name a star or a moon is selling you a certificate that no astronomer anywhere is obliged to honour.

References

1. The Literary Moons. NASA Science, Uranus Moons. https://science.nasa.gov/uranus/moons/
2. Moons of Uranus. BBC Sky at Night Magazine. https://www.skyatnightmagazine.com/space-science/uranus-moons
3. Why the moons of Uranus are named after characters in Shakespeare. The World, PRX. https://theworld.org/stories/2016/12/23/why-moons-uranus-are-named-after-characters-shakespeare