Arsenic: Poison and Building Block for Life?

The press conference announced last week by NASA promised to reveal details about “an astrobiology finding that will impact the search for evidence of extraterrestrial life.”

The news, that researchers conducting tests in the harsh environment of Mono Lake in  California had, according to NASA , “discovered the first known microorganism on Earth able to thrive and reproduce using the toxic chemical arsenic,” was indeed intriguing.