In 2010, a group of scientists claimed to have found bacteria that could build its DNA using arsenic, instead of the phosphorous used by the rest of Earth's life forms. Within days, the research behind "arsenic life" was under serious scrutiny and we now know that it was totally wrong. But the work was peer-reviewed. It was sponsored by NASA. How do so many experts make such a big mistake? Dan Vergano at USA Today has an excellent article looking at just that — and it includes the peer review comments that helped the arsenic life paper get published. Though normally secret, Vergano got a hold of them through a Freedom of Information Act request.