June 2012
edit
Welcome to Wikipedia. Although everyone is welcome to contribute constructively to the encyclopedia, adding or significantly changing content without citing a reliable source, as you did with this edit to Andromeda–Milky Way collision, is not consistent with our policy of verifiability. Take a look at the welcome page to learn more about contributing to this encyclopedia. If you are familiar with Wikipedia:Citing sources, please take this opportunity to add references to the article. DVdm (talk) 07:54, 15 June 2012 (UTC)