Penny Boston is one of the leaders of the SLIME team - that's Subsurface Life in Mineral Environments. She studies bizarre microorganisms that live, often under extreme conditions, in subterranean caves. At the recent NASA symposium "Risk and Exploration: Earth, Sea and the Stars," in Monterey, California, she talked about the relevance of her work below ground on Earth to the search for life on other worlds. She describes some of the cave environments she has explored and the life forms she has encountered and explains what caves can teach us about extraterrestrial life.
"I would venture to say that the bulk of the organisms that we find are novel; they're not known to science. From one little cave puddle to the next, we have perhaps 80 percent novel organisms.
These are truly evolutionarily self-contained environments. Many of them are physically isolated from the surface, little miniature planetary systemswithin our own crustal environment.
Not only do caves house these amazing arrays of organisms, but also they're wonderful preservation environments. Not only do the organisms live there, but they often self-lithify. They're engaged in self-fossilization while they're alive." [1]
Lake Vostok
Lake Vostok may be one of the most novel biomes yet to be tapped.
"Some years ago, researchers found something that sent shivers through the scientific community: a diverse community of microbial life-forms that live without sunlight or a ready supply of nutrients.
The scientists were not searching deep space when they made their find. Rather, they were sampling the bottom of a 2.5-mile-thick (4-kilometer-thick) Antarctic ice sheet.
The frozen mass covers Lake Vostok, a freshwater lake. Scientists demonstrated that the bottom layer of the ice sheet, the same one that contained the microbial life-forms, was composed of accreted, or frozen, lake water.
This, in turn, led scientists to suggest that a large, diverse community of microbes lived in the lake itself. If true, the theory would answer questions about the limits of life on Earth and expand the range of environments that might potentially host life-forms in space." [2]
Census of Marine Life
A host of record-breaking discoveries and revelations that stretch the extreme frontiers of marine knowledge were achieved by the Census of Marine Life in 2006.
They include life adapted to brutal conditions around 407°C fluids spewing from a seafloor vent (the hottest ever discovered), a mighty microbe 1 cm in diameter, mysterious 1.8 kg lobsters off the Madagascar coast, a US school of fish the size of Manhattan Island, and more unfamiliar than familiar species turned up beneath 700 meters of Antarctic ice. 2006 Report (PDF)