This website is primarily the home base of a project to develop a consistent set of symbols for every named astronomical body. But it is also a tribute to and exploration of all of the ways we symbolically render the heavens, and flags are a very common kind of symbol.

The use of "symbology" as a noun referring to a corpus of symbols isn't a very widespread, but there is hardly a more prominent example of an emergent symbology than that of flags — hence, the field of vexillology. I am hardly the first person to imagine what flags could exist for other planets, but according to a casual search I'm the first to propose the term astrovexillology.

Here I discuss some of the flags that have been developed for various astronomical bodies by professionals and amateurs alike, and explore how such flags ought to be developed.


There have been a number of proposals for flags of Earth. Many were developed by organizations or artists with peaceful intentions, with the notion of representing humanity as a collective whole. None exists in any official capacity, however, given the lack of a (non-consipracy theory) world government. Maybe the IAU has the authority to declare one, but that would probably be an overstepping of their duty. I digress.

The Earth flag proposal I like best is Oskar Pernefeldt's "International Flag of the Planet Earth," created in 2015 for the express purpose of representing humans of any nationality in space. It is a 2:3 flag, consisting of seven white interlocked rings on an azure background. The blue represents the terrestrial sea and sky, the rings represent the seven major continents, and the central details depict a flower, representing life on Earth.

Although it is sort of challenging to draw, I think it represents the Earth pretty well. Just don't go pledging allegiance to it yet.


Similarly, there is no official flag of Mars, not at least because nobody lives there. There are a number of flag propositions for this planet, as Mars is a favorite of science fiction writers. However, there is one flag that has reached a virtually ubiquitous status: the Martian tricolour invented by Pascal Lee in 1998.

The flag represents the present (red) and possible future through human settlement and terraforming (green and blue) of Mars. To be quite specific, the Pantone colors are "Red Clay" (18-1454), "Mint Green" (17-6333), and "Imperial Blue" (19-4245). The flag is optimistically used by the Mars Society and the Planetary Society, has been used in mock-ups and siimulations of Mars missions, and even flew on the STS-103 Discovery shuttle mission.

Some individuals have taken on the task of creating more astronomical flags, in projects that sort of parallel this one.

  • An artist called Wyrmshadow has a DeviantArt gallery named "Crazy Flags", some of which are flags for Solar System bodies based on the symbology of Denis Moskowitz.

Coming up with flag designs for tens of thousands of minor planets would be a task even more challenging than the one I am already in the midst of. Therefore, I think it would be nice to come up with a procedural method to develop minor planets flags as placeholders.

In Ted Kaye's Good Flag, Bad Flag, he provides five key principles for designing a good flag:

  1. Keep It Simple. The flag should be so simple that a child can draw it from memory…
  2. Use Meaningful Symbolism. The flag’s images, colors, or patterns should relate to what it symbolizes…
  3. Use 2 or 3 Basic Colors. Limit the number of colors on the flag to three which contrast well and come from the standard color set…
  4. No Lettering or Seals. Never use writing on any kind or an organization’s seal…
  5. Be Distinctive or Be Related. Avoid duplicating other flags, but use similarities to show connections…

I think these are pretty good guidelines; in fact, principles 1, 2, and 5 are almost exactly rules that I follow for the Night Sky Symbology.

Taking these principles as rules, here is the procedure for coming up with a simple 2:3 flag for each minor planet:

  1. Minor planets in our Solar System are assigned one of the above four flag designs, based on whether it is located in the asteroid belt (thirds), primarily crosses into the inner Solar System (circular center), is a Jupiter trojan or Hilda group (triangular pennant), or is a centaur/outer Solar System crosser/trans-Neptunian object (horizontal bars).
  2. Then, the asteroid symbol is placed in the center of the region denoted by the darker color above, encompassing a square with a side length of one-fifth of the flag width. Because no symbol is the left-right reversal of another symbol, the obverse and reverse sides of the flag do not introduce any ambiguity.
  3. Finally, the colors for the flag come directly from the predominant colors of the flag of the nationality of its referent. That is, if the referent or commemorant is a person or institution, the colors come from it's country of origin. If it is a character or piece of art, the colors come from the nationality of its creator. If the referent has no person or nationality associated with it, such as for mythological figures and abstract concepts, the nationality of the discoverer is used. Only the three most prominent colors are taken from that flag, to color each of the two regions and the symbol differently in a way that is pleasing to the eye. If the flag of nationality only has two colors, then the secondary region and the symbol must share a color.
  4. Arrange the colors in a way that is visually reminiscent of the original flag. All else equal, make the symbol the darkest color and make the dark region the lightest color.

This scheme generally produces decent-looking flags, but it may be that their general relatedness violates principle number 5. I can live with that. I consider these flags to be mainly placeholders anyway, just suggestions until someone with either a need or a responsibility comes along and designs a flag for some specific minor planet.

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