From NPR Science Friday a talk on Astrobiology and the Origins of Life.
This is before a live audience at Arizona State University, Tempe. So there is a lot of interaction between the scientists and the audience and also callers across the U.S. Guests are Peter Ward a biologist from Univ. of Washington, Paul Davies Cosmologist, Physicist, Astrobiologist from Arizona State Univ, Barry Blumberg Winner, 1976 Nobel Prize in Physiology or Medicine and Founding director, NASA Astrobiology Institute and Ariel Anbar, Principal Investigator, NASA Astrobiology Institute team at Arizona State University.
Two points stood out for me:
1) Where are earth rocks older than 4 billion years likely to be best preserved . Answer - The Moon! Early in the evolution of our solar system, meteorite bombardment of planets caused ejecta to travel and contaminate other planets and their satellites. On earth, rocks that old have been recycled and reconstituted , but the moon has been geologically inert for more than 4 billion years. About 1% of the Moon's soil is extraterrestrial in origin. So material from Venus, Earth and Mars is out there in the Moon's top soil layers.
2) Alien life does not necessarily mean life of extraterrestrial origin. There is the intriguing possibility that life evolved more than once on earth. Only one type proliferated, but is it possible other truly "alien" life forms, those that had an origin independent from our lineage still exist on earth? The point was made that most microbial life on earth has not yet been cataloged and we still have only a dim idea about life's variability. What would such "alien" microbes be made up of and what are the best places to look for them?
A very interesting topic and a great example of science outreach.
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