http://what-if.xkcd.com/73/ http://what-if.xkcd.com/73/ A nearby supernova would definitely be sterilizing to the kind of life found on Earth, and to a lot of

http://what-if.xkcd.com/73/ http://what-if.xkcd.com/73/ A nearby supernova would definitely be sterilizing to the kind of life found on Earth, and to a lot of other imaginable forms. Of course, "nearby" in astronomical terms is sometimes unintuitive. :-)