EXTRATERRESTRIAL:
Spirit, Stardust zero in on off-earth life
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NASA engineers enjoyed a double portion of jubilation Sunday and Monday as the robot Spirit began sending pictures from Mars and the Stardust probe sent a snapshot of the Wild-2 comet and collected a thimbleful of dust from the comet's tail, which is to be returned to Earth for analysis in 2006. While both technological marvels promise to expand human knowledge of the universe, the quest that underlies both expeditions is the quest for life beyond earth.
As an article in Monday's edition of Space.Com says, "As NASA prepares to set twin robots loose on the Martian surface and makes plans to send another in 2007, the agency's long term goal is clear: Determine whether the red planet does or ever did harbor life."
The Stardust probe is part of the same quest for life. Proponents of the panspermia theory suggest that comets could be a transmission belt for organic material or even living microorganisms from planet to planet. Many articles supporting that theory can be found in Brigham Klyce's Cosmic Ancestry website. Stardust could confirm this theory if it finds organic material in the comet's tail.
Hope for finding evidence of Mars life is bolstered by the discovery of bacteria living in extreme environments on earth in conditions similar to Mars. A recent issue of the journal Astrobiology says a bacteria discovered under the Siberian permafrost grows and reproduces in conditions as chilly as 14 degrees Fahrenheit (-10 degrees Celsius). Scientists figure that at certain times in the history of Mars, the tilting of its pole to a more oblique angle would have caused the north polar cap to warm enough to for such organisms to thrive.
Some scientists are already convinced that Mars harbors life based on evidence sent back by the first Mars landers and photos of the Mars surface taken by the Mars orbiter. An article in Cosmic Ancestry says, "The evidence sent back from Mars by two Viking Landers in 1976 and 1977 was not clear cut. In fact, NASA's first press release about the Viking tests announced that the results were positive. The 'Labelled Release' (LR) experiments had given positive results. But after lengthy discussions in which Carl Sagan participated, NASA reversed its position, mainly because another experiment detected no organics in the soil. Yet Gilbert V. Levin, the principal designer of the LR experiment, still believes the tests pointed to life on Mars. When the same two experiments were run on soil from Antarctica, the same conflicting results were obtained (LR - positive; organics - negative.) Soil from Antarctica definitely contains life. The test for organics was negative because it is far less sensitive than the LR experiment. The same problem could have caused the organics test on Mars to give a false negative."
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