The Cycle of Cosmic Catastrophies
By Richard Firestone, Allen West and Simon Warwick-Smith

    A large number of books have come out in recent years about ancient catastrophies.  This one stands out because the authors are all reputable scientists.  Firestone is a nuclear physicist, Warwick-Smith was a geologist and West was the owner of a scintific consulting firm.  The authors knew how to look for and verify evidence of their theory and were able to get other scientists to run tests for them.  This isn't a dull, technical thesis, however, but a very readable book put into language that we can all understand.  
    The primary theory of the book is that a major extinction event started on earth approximately 41,000 years ago and was caused by a supernova that occured about 200 light years away.  This resulted in the earth being bombarded very quickly with dangerous radiation, than the shock wave hit the planet thousands of years later, and then about thirteen thousand years ago the Earth was bombarded with debree from the exploding star as well as space dust and comets that were pushed toward us by the shock wave.  The authors provide very convincing evidence of this series of events that resulted in the extinction of many species including the mammoth and the saber tooth.
    I found this book fascinating and I recommend iit highly.  It has a five-star rating on Amazon.