This has been touched in forum #32614. Now I have some examples to illustrate the question about earth, moon, planet, saturn, star, sun, etc.
My own opinion is that it is okay for these tags to be ambiguous, so that saturn, for example, would cover the exact planet, its astronomical symbol, and the generic planet-with-rings symbol.
In any case, some wiki work is needed here. I like the wiki article for star, concise and clear. I would have had the same idea but written it in more detail and much more words.
Take a look at the following cases and discuss!
- The Sun, the Moon and the Earth as celestial bodies: post #492227
- The sun and the (crescent) moon as symbols: post #595032
- The moon, the sun and a star as (ahem) symbols: post #340462
- Stars in the sky: I just love this pic! post #373930
- In comic-style art, stars often have nothing to do with the space: post #586985
- Occasionally stars are seen in very different functions in one and the same pic: post #574443
- The planets of our solar system with their sun as pretty much themselves: post #32333
- These ones I would call more like symbols... True, I have seen even more iconic use of Saturn somewhere else. post #373050 & post #478575
- Getting extremely iconic, how would you tag astronomical symbols? http://en.wikipedia.org/wiki/Astronomical_symbols
- I am not into gaming, but I could have a wild guess at why this is tagged saturn: post #202688
Updated by Katajanmarja