As soon Redfield started to read the paper, she was shocked. “I was outraged at how bad the science was,” she told me.
Redfield blogged a scathing attack on Saturday. Over the weekend, a few other scientists took to the Internet as well. Was this merely a case of a few isolated cranks? To find out, I reached out to a dozen experts on Monday. Almost unanimously, they think the NASA scientists have failed to make their case. “It would be really cool if such a bug existed,” said San Diego State University’s Forest Rohwer, a microbiologist who looks for new species of bacteria and viruses in coral reefs. But, he added, “none of the arguments are very convincing on their own.” That was about as positive as the critics could get. “This paper should not have been published,” said Shelley Copley of the University of Colorado.
None of the scientists I spoke to ruled out the possibility that such weird bacteria might exist. Indeed, some of them were co-authors of a 2007 report for the National Academies of Sciences on alien life that called for research into, among other things, arsenic-based biology. But almost to a person, they felt that the NASA team had failed to take some basic precautions to avoid misleading results.
When the NASA scientists took the DNA out of the bacteria, for example, they ought to have taken extra steps to wash away any other kinds of molecules. Without these precautions, arsenic could have simply glommed to the DNA, like gum on a shoe. “It is pretty trivial to do a much better job,” said Rohwer.