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One thing I've never understood is why someone who seems as intelligent as you seems to be taken in by Digregorio. You are the only one who consistently seems to defend BD that makes sense most of the time or at least raises intelligent questions.

However, like GB I wonder what your point was in the post above.

Regards,
Mark
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Perhaps because he makes some good points. As I said Kenneth Nealson is probably the most knowledgable scientist around who knows both about extremophiles and Mars. He has been appointed as the director of the astrobiology division at JPL and he chaired the committee that wrote the prior National Academy of Sciences report on Mars Sample Return. He would certainly be aware of the recent research from several different and independent directions of likely near surface liquid water on Mars, active volcanism and therefore hydrothermal heating on the planet, and recent experiments suggesting the lack of sensitivity of the Viking GCMS to low levels of organics. Most importantly he would certainly be aware of their relevance to the question of life on Mars, especially in regards to his own research on the ability of extremophiles to survive harsh conditiions.
If you read the prior National Academy of Sciences report on Mars Sample Return it is remarkable how conditional their conclusions are. True they do suggest the likelihood of danger from such returned samples is low, but they state this conclusion is based on the idea of no liquid water, no volcanic activity, and no organics on the surface of Mars. It is important to keep in mind that the most recent research suggests that all three of these may not be correct. As a good scientist, Nealson can not simply ignore the fact the premises on which you based your conclusions may in fact be incorrect. As a good scientist he realizes that may mean, and in all likelihood does mean, your conclusions are also incorrect, IF IT IS FINALLY SHOWN THOSE PREMISES ARE INCORRECT. As a good scientist he realizes there should be further research to determine whether or not those premises are correct.

As I said, it is indeed notable that he now believes in situ life detection experiments should be conducted on Mars before a sample return mission, in agreement with Digregorio and Levin.

Bob Clark