Have you read 'The Mars Mystery' by Graham Hancock??
Here is a piece taken from his website........
Johannes Kepler, the 17th century astronomer and mathematician, once exclaimed that 'there are more comets in the sky than there are fishes in the sea'. In 1990, a NASA astronomer observed that 'there are more professionals working in a single fast-food restaurant than there are professionals scanning the sky for asteroids.'
The search for earth-bound space debris has traditionally received only minimal funding and although improvements are planned they may be too little and too late. With inadequate technology and personnel, it is frighteningly unlikely that our lookouts will spot an earth-bound object in sufficient time for us to do anything about it. The developed world is in a complacent slumber, and neither fantastical Hollywood movies nor dry probability estimates can awaken it to the reality of impending disaster.
In The Mars Mystery, Hancock, Bauval and Grigsby try something very different - they develop a firmly historical perspective on a catastrophe we have yet to experience.
The story begins with Mars. The authors examine and approve the theory that our planetary neighbour once held a dense atmosphere and oceans of water but was extinguished with incredible violence by a barrage of rock many thousands of years ago. They also provide an up-to-date, comprehensive and refreshingly balanced review of the photographic evidence regarding the past existence of a Martian civilisation. Equally absorbing is the investigation into NASA's handling of the controversy surrounding the photographs, which included the issuing of false statements. The authors relate this to the history of disinformation policies pursued by American defence institutions.
The scope of the book then broadens to cover the impacts that have involved Earth, our Moon and the other scarred bodies in our solar system. The reader may be shocked to discover that our Moon is literally still vibrating from an impact that was observed by shocked Earthlings hundreds of years ago. A particularly compelling chapter, incorporating evidence from a number of respected astronomers, concerns a swarm of comets, including a giant one up to 300 kilometres across, that entered an Earth-crossing orbit around 50,000 years ago. The giant comet subsequently fragmented, flooding the orbital path with millions of lethal asteroids and vastly increasing the chances of a collision with Earth. In fact, in all probability Earth has already been hit by one of these fragments in the last 20,000 years. Here the place of The Mars Mystery amongst Hancock's other titles becomes clear. Could such an impact have been behind the dramatic and hitherto unexplained end of the last ice age? Could the survivors of that cataclysm have passed down, to all the great post-ice age civilisations, a warning of what is to come? There is an abundance of historical, archaeological and geological evidence, summarised in The Mars Mystery (and covered in more depth in Fingerprints of the Gods), to suggest the affirmative.
With effectiveness lent by its historical perspective, The Mars Mystery turns implausibility into intrigue and invites both dread and hope. Will it wake us up? At least it's a start ...