| MadSci Network: Cell Biology |
In my opinion, it is possible, although highly unlikely. Mars's atmosphere consists of a thin layer of carbon dioxide and a trace of oxygen. These are the gasses that support life on earth. Theories say that there is some water on Mars, and that at one time it was warm enough for the water to be liquid. During this period of time, simple life forms could have evolved. They would have had to adapt quickly as Mars cooled and its atmosphere thinned. If there are any life forms on Mars today, they are probably bacteria that use sunlight, living a few millimeters beneath the surface of rocks. This type of life form exists in the arctic regions of earth. Another possibility is that there may be simple organisms that became dormant as Mars cooled, and have never became active again. Some Earth bacteria can stay dormant for centuries, so why couldn't martian bacteria? Life probably existed on Mars at one time: The recent discovery of what seems to be life in a meteorite from Mars supports that life once existed on Mars. The meteorite was blasted from Mars many millennia ago by an asteroid. It then crashed to Earth in Antarctica. Analysis of the meteorite shows carbonate minerals, deposited by water, that are similar to those deposited in hot springs on earth. The meteroite also contains a type of chemical called polycyclic aromatic hydrocarbons. The processes that would form these compounds are either star formation or formation of coal from organic compounds. These pockets of organic compounds are in rod shapes in patterns followed by bacteria in the hot springs on earth. Some say that these deposits could have formed by other means. Other compounds often associated with bacteria on Earth that occur in the Martian rocks are iron sulfide and magnetite. For more information on the Mars rocks, click here. Keep those questions coming! Matthew Barchok, Mad Scientist