Thursday, February 24, 2005
Life on Mars?
First came the story about the ancient equatorial ice ocean discovered by the European space agency's Mars Express space craft, as reported in the National Geographic. Then came the story about frozen organisms right here on earth.
A U.S. scientist claims to have thawed out a new life form, which he said raises 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. 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.
The ice wedges contained a golden-brown layer about a half-yard (half-meter) thick, and this 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, Hoover said, "These 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."
Combine the two discoveries and the odds of actually finding some form of life (most likely bacterial) on Mars improve dramatically.
A U.S. scientist claims to have thawed out a new life form, which he said raises 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. 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.
The ice wedges contained a golden-brown layer about a half-yard (half-meter) thick, and this 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, Hoover said, "These 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."
Combine the two discoveries and the odds of actually finding some form of life (most likely bacterial) on Mars improve dramatically.
