Astronomical/Astrological symbols for other planets' moons

There are astronomical symbols for each of the 9 planets in our solar system, as well as for the Sun, the Moon, and some of the asteroids. However, I have not been able to find any symbols for the moons/satellites of other planets.

Astronomers, as far as I can tell, use the symbol of the planet plus a roman numeral indicating which orbit the moon is in. This is all well and good, but not very interesting or evocative. Astrologers, on the other hand, have no real reason to have separate symbols for the moons, since they are always in effectively the same part of the sky as their planet (when seen from Earth).

As someone who enjoys thinking about possible lifestyles of the future, I imagine a time when the outer planets will be inhabited, or at least have astrologically interesting events happening on them. (I'm not a believer in astrology myself, but find it interesting.) Future astronomers and astrologers may wish to have symbols for the moons of the planet they are inhabiting or orbiting.

I have invented symbols for 26 of the other moons. My general method is to take some aspect of the planetary symbol and apply it to symbols differentiating the moons, usually the initial of the moon's name in the appropriate writing system. I offer these symbols up to the public domain, for use by future astronomers, future astrologers, and anyone else who's interested.


Mars

Mars

Mars has two moons, Phobos and Deimos. The symbols for them are based on the lower-case versions of the Greek letters Phi and Delta, which begin those two names in the original Greek, with the arrow from Mars's symbol added on.


Phobos astrological/astronomical symbol
Phobos
Deimos astrological/astronomical symbol
Deimos


The Jovian planets

The Jovian gas giants each have a large number of moons (at least 13 for Neptune, at least 63 for Jupiter). It's not really feasible to include them all, but some are larger than others. I've chosen an admittedly arbitrary threshold of 10 Zg (1019 kg) and created symbols for any moon larger than that, which lets in Saturn's moon Hyperion but not Jupiter's largest non-Galilean moon Amalthea. This is also near the point at which moons become non-spherical - there are some non-spherical objects above this line, but no spherical ones below.


Jupiter

Jupiter

Jupiter has four "large" moons - the four Galilean moons. For their symbols, the Greek letter beginning their names is combined with the cross at the bottom of the symbol for Jupiter.
Io astronomical astrological symbol
Io
Europa astronomical astrological symbol
Europa
Ganymede astronomical astrological symbol
Ganymede
Callisto astronomical astrological symbol
Callisto


Saturn

Saturn

Saturn has 8 "major satellites". (They are all spherical except Hyperion.) From a suggestion by my brother Marc Moskowitz, I've combined the Greek letter beginning their names with Saturn's hook. I've used the lower-case rho instead of the capital for aesthetic reasons. Titan and Tethys both begin with tau, so Titan has a circle around its intersection to symbolize its atmosphere.
Mimas astronomical astrological symbol
Mimas
Enceladus astronomical astrological symbol
Enceladus
Tethys astronomical astrological symbol
Tethys
Dione astronomical astrological symbol
Dione
Rhea astronomical astrological symbol
Rhea
Titan astronomical astrological symbol
Titan
Hyperion astronomical astrological symbol
Hyperion
Iapetus astronomical astrological symbol
Iapetus


Uranus Uranus

Uranus

Uranus has two symbols, both of which include a circle at the bottom. Its moons are named after characters from English literature. Here are symbols for the 5 major satellites, based on the initial of the moon (from the roman alphabet) combined with the lower circle from the symbol for Uranus. (I've used the empty circle from the "H" symbol - if you prefer the arrow symbol, feel free to add the central dot.)
Miranda astronomical astrological symbol
Miranda
Ariel astronomical astrological symbol
Ariel
Umbriel astronomical astrological symbol
Umbriel
Titania astronomical astrological symbol
Titania
Oberon astronomical astrological symbol
Oberon


Neptune

Neptune

Neptune has 3 "major" moons - Triton, which is the 7th largest moon in the Solar system, and the non-spherical Nereid (31 Zg) and Proteus (50 Zg). Their symbols combine the Greek letter beginning their names and Neptune's trident.
Proteus astronomical astrological symbol
Proteus
Triton astronomical astrological symbol
Triton
Nereid astronomical astrological symbol
Nereid


PlutoPluto

Pluto

Pluto has two symbols, one usually used by astronomers and one usually used by astrologers. The astronomical symbol is a combination of the letters P and L, both for the planet PLuto and in honor of Percival Lowell. The astrological symbol is a circle inside an arc above a cross.

Pluto has three moons: Charon, Nix, and Hydra. Charon was discovered by James Christy and named to honor his wife Charlene, so a symbol combining C and H is the obvious choice for an astronomical symbol. The astrological symbol uses the floating circle from Pluto and applies it to a sideways crescent, referencing both Charon being a moon and Charon's mythological meaning as a boatman across the river of the dead. (A version of this symbol is apparently already a less common symbol for Pluto.) Nix is either a misspelling of the Greek goddess Nyx, in which case it starts with Nu, or Latin for "snow", which starts with N. Luckily capital Nu and capital N look the same. Hydra begins with Upsilon in Greek.


Charon astronomical symbol
Charon (astronomical)
Nix astronomical symbol
Nix (astronomical)
Hydra astronomical symbol
Hydra (astronomical)
Charon astrological symbol
Charon (astrological)
Nix astrological symbol
Nix (astrological)
Hydra astrological symbol
Hydra (astrological)

Eris

Eris

Eris has no official symbol, but I suggest one on my page of symbols for TNOs. Since Eris is as much of a planet as Pluto, I felt its moon Dysnomia merited a symbol as well. Eris's symbol is two curvy arrows colliding, so Dysnomia's symbol is two curvy Deltas colliding.


Dysnomia astronomical astrological symbol
Dysnomia

Smaller versions of the moon images:
Phobos astronomical astrological symbol
Phobos
Deimos astronomical astrological symbol
Deimos
Io astronomical astrological symbol
Io
Europa astronomical astrological symbol
Europa
Ganymede astronomical astrological symbol
Ganymede
Callisto astronomical astrological symbol
Callisto
Mimas astronomical astrological symbol
Mimas
Enceladus astronomical astrological symbol
Enceladus
Tethys astronomical astrological symbol
Tethys
Dione astronomical astrological symbol
Dione
Rhea astronomical astrological symbol
Rhea
Titan astronomical astrological symbol
Titan
Hyperion astronomical astrological symbol
Hyperion
Iapetus astronomical astrological symbol
Iapetus
Miranda astronomical astrological symbol
Miranda
Ariel astronomical astrological symbol
Ariel
Umbriel astronomical astrological symbol
Umbriel
Titania astronomical astrological symbol
Titania
Oberon astronomical astrological symbol
Oberon
Proteus astronomical astrological symbol
Proteus
Triton astronomical astrological symbol
Triton
Nereid astronomical astrological symbol
Nereid
Charon astronomical symbol
Charon
Nix astronomical symbol
Nix
Hydra astronomical symbol
Hydra
Charon astrological symbol
Charon
Nix astrological symbol
Nix
Hydra astrological symbol
Hydra
Dysnomia astronomical astrological symbol
Dysnomia

To see these symbols in context with other ones, I've created a list of the largest named objects in our solar system, with a symbol by each object. I've also used the Phobos and Deimos symbols in natal charts for the NASA rovers Spirit and Opportunity.


This page and these graphics by Denis Moskowitz. Last modified Thu Oct 5, 2006. The symbols are given to the public domain and may be used freely, copied, redrawn, critiqued, etc. but please don't claim credit for them.