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Taking a Hit: Asteroid Impacts and Evolution

Dr. David MorrisonOctober 3, 2007

Dr. David Morrison (NASA Ames Research Center)

Listen (mp3 file, 18.9 MB)

Asteroids have hit the Earth many time in the past, and they will continue to hit in the future, whether we are prepared or not. Collisions with our planet over 4.5 billion years have profoundly influenced the evolution of life. (In fact, were it not for the impact of a 15-km wide asteroid 65 million years ago, it is likely humanity would not be here.) Dr. Morrison, one of the world’s experts on the study of asteroid impacts, discusses the past and the future of these catastrophic hits, and explains how, in the last two decades, we have learned (in principle) how to defend ourselves. Unlike other natural hazards, we now have the capability of removing most of the impact risk within the next generation. However, the government still does not have a plan of action for when an asteroid is discovered heading our way or when an impact happens without any warning. (We recommend you listen to this podcast holding hands with someone you love.)