(Hmmm... It's not dated 1st April...)
A Cuneiform clay tablet which for over 150 years defied attempts at interpretation has now been revealed to describe an asteroid impact which in 3123 BC hit Köfels, Austria, leaving in its wake a trail of destruction which may acccount...
More: http://www.theregister.co.uk/2008/03/31/kofels_asteroid/