For questions related to outer space, stellar systems, stars and other astronomical phenomena.
"Space" has historically been a shortened version of the term "outer space", which is regarded as the area beyond Earth's atmosphere, or, more accurately, above the Kármán line. This tag is for questions related to outer space, planetary systems and stars. Do not use this tag merely because it relates to spatial dimensions. Also consider the more specific planets, stars and astronomy tags: if you're asking about one planet or one star or similar, it is likely that the space tag is not specific enough.