Scientists are trying to figure out if life came from space. This theory would be strengthened if we found evidence that there is?or ever was?life on Mars. When we sent a Viking lander there to do tests, the results were inconclusive. Now we've found soil in one of the oldest and driest deserts in the world?the Atacama Desert in Chile?that's a close match to the red soil of Mars. It may help us figure out if there's life on Mars.
Helen Briggs writes in bbcnews.com that the dirt in this desert has similar chemical properties to the dirt on Mars. Tests on this soil may explain the strange findings from the chemical tests done on samples taken by the Mars Viking mission in 1976. A biology experiment on Viking 1 detected signs of activity in Martian soil that seemed like microbes giving off gas, but further tests failed to find carbon, so scientists concluded that Mars is a dead planet. Which conclusion is true?
"The commonly held interpretation of the Viking results is that the soil was chemically, but not biologically active," says NASA's Richard Quinn. When researchers repeated the Viking experiments on the Atacama soil, they came up with the same results they got on Mars. But they also found tiny traces of organic matter in the desert soil, at lower levels than they would have been able to detect on Mars, so it's possible that there is organic matter on Mars after all.
"Currently, the unanswered question is whether Viking failed to detect certain types of organic compound on Mars," says Quinn. "Our work suggests that this may have been the case. However, new experiments would need to be done on Mars to answer this question."
So finding similar soil on Earth only deepens the question of whether there's life on Mars. But it does provide a good place to do practice testing on new equipment for future Mars missions?so they can answer the question next time. Quinn says, "We hope to use these instruments on Mars to identify soils that may have contained life at some point in the planet's history."
Life?where else does it exist, and is it trying to tell us something? Decide for yourself by looking at the exquisite photos in our wonderful new 2004 crop circle calendar. These make wonderful Christmas gifts and we're the only place you can get them here in the U.S.
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