Two excerpts from http://www.scientificamerican.com/artic ... lean-rooms
The researchers named the bacterium Tersicoccus phoenicis. “Tersi” is Latin for clean, as in clean room, and “coccus” comes from Greek and describes the bacterium in this genus’s berrylike shape. “Phoenicis” as the species name pays homage to the Phoenix lander. The scientists determined that T. phoenicis shares less than 95 percent of its genetic sequence with its closest bacterial relative. ...
There is no proof that T. phoenicis actually accompanied Phoenix to Mars, but it is possible. “This genus has surely traveled to Mars already, recently in one or more of our spacecraft—they live comfortably in the clean rooms where we build the craft, right?—and maybe even onboard meteorites millions or billions of years ago,” Fairén says. “Therefore, if these bugs can actually survive on Mars, they must be there already.”
That this bacterium shares "less than 95 percent of its genetic sequence with its closest bacterial relative" is significant. Surely, there must be other species or varieties of this bacterium elsewhere perhaps in hot volcanic pools of water on earth where no life is suspected. Death valley could also be harboring these lowly life forms.
Not answered: is this bacteria benign? That is the question that needs to be answered.
From my studies in microbiology, usually the most heat resistant bacteria are friendly.