Microbes of three different kinds have been found living in the wind-swept, snow-free valleys of Antarctica where life had never been found before.
Algae, bacteria and fungi have been discovered hidden just below the surface of rocks strewn over more than 100 locations in the frozen deserts of the Antarctic, where the climate is so dry that even a light dusting of snow is a rare occurrence.
"We have been looking for life forms in the world's deserts for 15 years and this is the first time we have found life in a cold desert," said Florida State University's Dr. E. Imre Friedmann, who made the findings with his wife, Roseli Ocampo-Friedmann. "The surprising thing is that the life we find in the Antarctic is less primitive and has more variety than life found in the hot desert."
The finding of life in Antarctica's dry valleys extends the known limits of life on Earth to its driest and coldest climate. At the same time, the discovery suggests the same kind of life may exist inside the rocks of a planet like Mars, where the climate closely resembles the dry valleys of Antarctica.
"If Martian life forms exist only in the interior of Martian rocks, as is principally the cse in the Antarctic, that could serve as an explanation for the lack of evidence for life on Mars," said Dr. Richard S. Young, chief of planetary biology for the National Aeronautics and Space Administration. "The two Viking spacecraft that landed on Mars could not break open rocks and analyze their interiors."
What Friedmann and his wife did on field trips the last two summers to the dry valleys was to heat rock samples until they broke apart and their outer layers could be peeled away. Widespread colonies of microbes were found fractions of an inch below the rock surfaces, where sunlight could penetrate and moisture might reach.
Friedmann said he believes the microbes found the rocks have been there for at least 200.000 years, ever since the dry valleys reached their present climate conditions. He said he thinks the microbes burrowed into the rocks through cracks and pores, then swelled outward just below the rocks' out layers.
The Florida State biologists said he thinks the microbes thrive on nitrogen that leaks out of the atmosphere through cracks in the rocks, on minute amounts of minerals in the soil covering the rocks and on tiny traces of moisture that melt into the rocks from the little snow that falls in the dry valleys.