Bacterial find points to life on red planet

[macmax]

Washington: An American scientist claims to have thawed out a new life form, which, he said, raised questions about possible contemporary life on Mars.

“The organism froze on Earth some 30,000 years ago and was apparently alive all that time and started swimming as soon as it thawed,’’ Richard Hoover from the National Aeronautics and Space Administration’s (Nasa) Marshall Space Flight Center in Alabama said. The life form—a bacterium dubbed Carnobacterium pleistocenium—probably flourished in the Pleistocene Age along with woolly mammoths and saber-tooth tigers, said Hoover.

He discovered the bacterium near the town of Fox, Alaska, in a tunnel drilled through permafrost—a mix of permanently frozen ice, soil and rock—that is kept at a constant temperature of 24.8 degrees Fahrenheit (minus 4 degrees Celcius). “When they cut into the Fox tunnel, they actually cut through Pleistocene ice wedges, which are similar to structures that we see on Mars,’’ Hoover said in a telephone interview.

He added that the ice wedges contained a golden-brown layer about half-yard (half-metre) thick, and the layer contained a group of microscopic brownish bacteria. Hoover said when he looked at a small sample of this bacteria-laden ice under a microscope, “the bacteria that had just thawed out of the ice ... were swimming around. The instant the ice melted, they started swimming. They were alive ... but they had been frozen for over 30,000 years’’.

This discovery, coupled with research released this week by the European Space Agency, makes it more likely that life could be found on Mars, Hoover said.

Scientists have focused on Mars as the most likely spot in our solar system for Earth-like life, but none has been confirmed so far. What has been found is ample evidence that water once flowed on this currently cold and frost-locked planet. This is significant because liquid water—not ice—has been seen as a prerequisite for life as it is known on Earth.

Images made by the European Mars Express space probe indicate a giant frozen sea near the Martian equator, the first time scientists have detected evidence of ice beyond Mars’ polar caps.

According to Hoover, this vast sea is covered by a layer of dust, which may be heated by the sun and could conduct heat down to create sub-surface layers of water from time to time.

“Those layers will be ideal regions for microbiological activity. That means that the presence of this frozen sea, if that turns out to be precisely what’s going on, greatly enhances the possibility that there may be life existing on Mars today,’’ he said, adding that the discovery of the living bacteria in Alaska’s permafrost raises another possibility too. “The other thing that’s exciting is frozen biology in the form of unicellular bacteria might even have remained alive, frozen in the Martian sea,’’ he said. Hoover found the bacterium in 2000, but it took five years to confirm that it was in fact a new form of life.

The finding was published in the January edition of the International Journal of Systematic and Evolutionary Microbiology, the official journal of record for such matters. Reuters