links for 2010-02-25

Good analysis [via @atmaspere]

"The possibility of strange forms of alien life seems to have just got a whole lot closer to home. Astrobiologists from Arizona State University, Florida, UC Boulder, NASA, Harvard and Australia have recently theorized about a “shadow biosphere” – a biosphere within a biosphere where alternative biochemistry may be thriving in a way that we haven’t yet thought to examine." [via @rnaworld]