Methane doesn't necessarily mean life on Mars, says Dartmouth studyJune 08, 2005Two Dartmouth researchers have weighed in on the debate over whether the presence of methane gas on Mars indicates life on the red planet. Mukul Sharma, Assistant Professor of Earth Sciences, and Chris Oze, a postdoctoral fellow, argue that the Martian methane could have been produced by inorganic processes just as easily as by bacteria. In their paper published online in May in the American Geophysical Union's journal, Geophysical Research Letters, Sharma and Oze describe how methane on Mars can be made from abiotic, or non-living, sources. When water containing dissolved carbon dioxide comes in contact with olivine, it produces hydrogen, which then combines with carbon dioxide to produce methane. The authors contend that olivine is abundant on Mars at shallow depths, and it could easily react with fluids just beneath the surface. "Most methane on Earth is produced by bacteria, and methane has been cited as an indicator of life on other planets," explains Sharma. "However, we show in our paper that the mineral olivine can be altered in the presence of water and carbon dioxide, which can produce copious quantities of methane. It's quite easy to do, and there is nothing bacterial about it. If there is life on Mars, I would like to see better evidence than methane." The paper also provides a plausible explanation for a warmer and wetter early Mars. Recent results from rover missions on Mars have pointed to the presence of flowing water on the planet's surface. It is, however, impossible to heat the planet's surface to above freezing temperatures by greenhouse action of carbon dioxide alone. The authors estimate that the abiotic creation of methane via the altered olivine was very efficient due to a higher surface heat flow and more intense hydrothermal circulation. Sharma and Oze say that methane, a very effective greenhouse gas, would have been more abundant in the atmosphere resulting in a climate that was warm enough to allow liquid water to be present on the Martian surface. Dartmouth College |
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| Related Life On Mars Current Events and Life On Mars News Articles Mars, methane and mysteries Mars may not be as dormant as scientists once thought. The 2004 discovery of methane means that either there is life on Mars, or that volcanic activity continues to generate heat below the martian surface. Caltech, JPL scientists say that microbial mats built 3.4-billion-year-old stromatolites Stromatolites are dome- or column-like sedimentary rock structures that are formed in shallow water, layer by layer, over long periods of geologic time. The minerals on Mars influence the measuring of its temperature A team of researchers from the CSIC-INTA Astrobiology Centre in Madrid has confirmed that the type of mineralogical composition on the surface of Mars influences the measuring of its temperature. Many characteristics of Mars, including ice, are similar to Earth, paper says Mars gets as far as 250 million miles away, but many parts of it closely resemble places on Earth, including its landscape, history of water, soil and even its weather, says a Texas A&M University researcher in the current issue of "Science" magazine. University of Colorado team finds definitive evidence for ancient lake on Mars A University of Colorado at Boulder research team has discovered the first definitive evidence of shorelines on Mars, an indication of a deep, ancient lake there and a finding with implications for the discovery of past life on the Red Planet. What to do with rotten, smelly garbage when the nearest dumpster is 100 million miles away No one takes out the trash in space. In the cramped living quarters of a space station, garbage can pile up, spoil and become a health hazard for astronauts. Sensitive laser instrument could aid search for life on Mars Minuscule traces of cells can be detected in a mineral likely present on Mars, a new study shows. The results, obtained using a technique developed at the U.S. Department of Energy's Idaho National Laboratory, could help mission scientists choose Martian surface samples with the most promise for yielding signs of life. Laser fluorescence could find life on Mars A team of scientists from the United States and the United Kingdom has developed a technique using ultraviolet light to identify organic matter in soils that they say could be used to document the existence of life on Mars. For the paper trail of life on Mars or other planets, find cellulose Looking for evidence of life on Mars or other planets? Finding cellulose microfibers would be the next best thing to a close encounter, according to new research from the University of North Carolina at Chapel Hill. Liquid water found flowing on Mars? Not yet Liquid water has not been found on the Martian surface within the last decade after all, according to new research. More Life On Mars Current Events and Life On Mars News Articles |
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