The istory of the stronomical lphabet

(and other trivia)

The History

1) Back in the mid-1970's I first saw pictures of "S" and "Barnard's E" which are both pretty well-known dark clouds in the Milky Way. Photos of "S" especially are a pretty commonly found in basic astronomical texts.

2) Later, during graduate school in the late 1980's, while working with data from the IRAS mission I was introduced to the "G" shape of supernova remnant IC 443. At about the same time (plus or minus a few years) I saw pictures or posters of the butterfly alphabet. Still at this time, it hadn't occured to me that an Astronomical Alphabet was feasible.

3) Then sometime in 1998 or 1999, I set my computer's desktop picture to an image of the Hubble Deep Field. After seeing that picture every day for months, it's impossible to not notice the "Z" galaxy and the "L" group of galaxies. But still the idea of the full alphabet hadn't clicked.

4) What finally sparked the possibility was the 1999 Chandra X-ray image of supernova remnant 1E0102-543 which was an obvious Q. At that point I finally realized that I knew quite a few astronomical letters, and maybe it wouldn't be too hard to locate the rest.

5) So on the long Thanksgiving Day weekend in 1999, I set out through miscellanous textbooks and across the internet to collect the astronominal alphabet. S, E, G, Z, L, and Q were there at the start (with only the minor task of finding an electronic image of S and E). Among the next easy and obvious choices were a crescent moon or planet for C (I was hoping for a Crescent Callisto C, but settled for Titan) [I've now found a crescent Callisto!], a quarter phase planetary image for D, an annular eclipse for O, and the separate ion and dust tails of a comet for V. A solar prominence was another easy pick for U, but a really lucky find was catching a good B in the very same image of the Sun! I'm not sure where I would have found a B otherwise. Then browsing the Hubble archives (nice because they're sharp, colorful images of complex objects) turned up A, P, T, W, and X, all without too much trouble. I sought out pictures of barred spirals to get an I, and along the way figured I could use another spiral for N (which is a lot like Z). Finding a hooked jet for J came to mind pretty quickly, and the nice images and web site were quickly found too. Getting toward the end, I figured that if I looked hard enough at the complex filaments of the Cygnus Loop (yet another supernova remnant) I ought to find something. K popped up. Similarly, touring about maps of Venus and Mars led to F, H, M (appropriately on Mars), and Y. On both planets, I had started with some ideas of places that might be suitable, and my hunches paid off. (Alas looking for letters on Europa didn't fare as well. If there's any life under Europa's global icecap, it doesn't seem to be leaving grafitti on the surface.) Finally it was back to the Sun to look for a suitably loopy and spiky region of solar activity to pass as R.

7) So that's the story -- a letter here, a letter there, and then suddenly a whole lot of letters at once. I was pretty suprised to be able to find it all in that long 4-day weekend, and have time to put the initial page together too. I'm also quite pleased with the pretty balanced range of colors that turned up in the images.

The Trivia

I was not inspired enough to search out numerals 0,1,2,3,4,5,6,7,8,9, or lower case letter. Numbers quantify things, but they can't be used to convey ideas the way letters do. The lower case letters are often too similar to the upper case letters, or depend on small details to be distinguished.

This also brings up the possibility of Astronomical Alphabets in other languages, e.g. Arabic, Greek, Hebrew, Cyrillic. Somehow these other alphabets seem more daunting. They contain letters that are either very complex in appearance or defined by small details. They strike me as being much harder to find by chance, though I may be biased since I don't make regular (or any) use of any other alphabets other than the English and Greek (for math only!) ones. That said, I will point out that the "B" actually is a better lower case Greek beta, or a German ess-tsett. I also stumbled across a lower case Greek zeta that is really quite impressive:

Back to the Astronomical Alphabet

By Rick Arendt. October 3, 2000, updated August 20, 2002