Gizmodo:

NASA has discovered a completely new life form that doesn't share the biological building blocks of anything currently living in planet Earth, using arsenic to build its DNA, RNA, proteins, and cell membranes. This changes everything. Updating live.

NASA scientist Felisa Wolfe Simon and her team have found a bacteria whose DNA is completely alien to what we know today. Instead of using phosphorus, the bacteria uses arsenic for all its building blocks.

Even if this is true, I'm not at all surprised. The idea has been floating around the origins-of-life community for sometime. Also, I would not be surprised if those "aliens" are manmade. Also, anyone who is familiar with evolutionary development—meaning, with the very strangeness of animal life—will be interested in but not amazed by this discovery. Just think about this small part of "ordinary," phosphorus-based evolution: two of the three bones in the human ear were not originally used for hearing but were the jaw bones of reptiles—yes, small jaw bones were slowly appropriated by the ear organ. The human being is a walking zoo.

The NASA story is here:

"We know that some microbes can breathe arsenic, but what we've found is a microbe doing something new — building parts of itself out of arsenic," said Felisa Wolfe-Simon, a NASA Astrobiology Research Fellow in residence at the U.S. Geological Survey in Menlo Park, Calif., and the research team's lead scientist. "If something here on Earth can do something so unexpected, what else can life do that we haven't seen yet?"