Not to argue with The Alchemist, as he certainly is more informed on this topic than I am, but...

Scientific American has reported the discovery of a new colony of Archaea existing in hydrothermal water inside of the igneous rock beneath a mountain range in Idaho.

This is signifigant because this sort of environment is what is believed to exist beneath the surface of Mars. These particular microbes have evolved to exist without sunlight by gaining energy through the production of methane gas by combining hydrogen with carbon dioxide.

The implication, in case you missed it, is that similar life could theoretically exist on Mars, or other planets with similar subsurface-chemistry.