books.google.com.mx - A lively astronomy primer that uses cataclysmic scenarios to explain the universe?s most fascinating events. According to astronomer Philip Plait, the universe is an apocalypse waiting to happen But how much do we really need to fear from things like black holes, gamma-ray bursts, and supernovae? And...http://books.google.com.mx/books/about/Death_from_the_Skies.html?id=hH068NFwwIkC&q=protons&utm_source=gb-gplus-shareDeath from the Skies!
