Tya

The correct title of this article is tya. The initial letter is shown capitalized due to technical restrictions.

"Kya" redirects here. For other uses, see Kya (disambiguation).

In astronomy, geology, and paleontology, tya, sometimes also kya, is an acronym for thousand years ago and is used as a unit of time to denote length of time before the present. The popular term 'kya' is replaced in scientific literature with ka (kilo annum).