If you were hoping NASA was going to announce the very first tweet from an extraterrestrial being, sorry to break your heart -- it is astrobiological, but the findings are actually borne of this rock. Researchers in Mono Lake, California, have discovered a microorganism (pictured) that uses arsenic instead of phosphorous to thrive and reproduce. The latter, as far as terrestrial life is concerned, is a building block of life along with carbon, hydrogen, nitrogen, oxygen, and sulfur, all integral to our DNA and RNA. Arsenic, meanwhile, is generally considered poisonous -- but "chemically it behaves similarly to phosphate," apparently making for a good substitution. In other words, NASA's proven that life can be made with components different than our current assumptions, both locally and beyond the stars. Seems entirely logical, if you ask us. (A silicon-based Horta, Mr. Spock?)

So, what about other atypical life-forming chemicals? NASA isn't speculating. That sound you hear is a thousand light bulbs popping up as science fiction writers everywhere conjure up brand new super villains -- and a thousand Chemistry professors writing new extra credit questions for their fall semester finals.