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First you would die, either from asphyxiation or hypothermia. Mars's carbon dioxide atmosphere is 100 times less dense than Earth's and the average surface temperature is -60 deg C. The exact cause of death would depend on the season, the time of day (Martian temperatures fluctuate as much as 100 degrees from dawn to dusk), and the latitude of your surprise landing site. Next you would begin to dry out. There is no liquid water on the surface of Mars and little, if any, water vapor in the atmosphere. Your lifeless body would become dessicated like an Egyptian mummy. Finally, not that it would matter terribly, you would contract a very nasty sunburn. The Red Planet's rarefied atmosphere does a poor job blocking UV rays from the sun (there is no protective ozone layer in the atmosphere). Radiation levels are so intense that they probably sterilize the uppermost layers of Martian soil. The next time you visit Mars, take a space suit.
The reality of this picture is somewhat controversial, but if it is true, it seems likely to many scientists that early Mars could have teemed with simple forms of life.
Farmer (formerly of NASA/Ames) along with his collaborators at ASU, is a pioneer in the new scientific discipline called exopaleontology -- the search for signs of primeval life on other planets. "Mars may harbor the best preserved rocks in the solar system," he continued. "For example, the Allan Hills meteorite [an ancient potato-sized rock from Mars that crashed into Antarctica 13,000 years ago] is nearly 4.6 billion years old. The fossil record on Mars might go all the way back to the earliest history of the planet." Farmer says he wouldn't mind visiting Mars to prospect for fossils in person, but an unmanned probe is likely to be the first exopalentologist on the Red Planet. Where should a Mars lander set down to seek out the elusive fossil record? The answer to that question may be found here on Earth in an other-worldly place called Mono Lake. ![]() Mono Lake"Mono Lake lies in a lifeless, hideous desert ... This solemn, silent, sailless sea - this lonely tenant of the loneliest spot on earth - is little graced with the picturesque."Mono Lake in California is nearly 700,000 years old, making it one of the oldest lakes in North America. Throughout its long existence, salts and minerals have washed into the lake from Eastern Sierra streams, but there is no outlet. Fresh water evaporating leaves behind salts and minerals so that now Mono Lake is about 2 1/2 times as salty and 80 times as alkaline as the ocean. Swimmers in the lake find that they literally cannot sink (dissolved carbonates, chlorides and sulfates make floating easy) but their skin does tend to bleach and burn in the alkaline water.
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The Red Planet in 3D -- New data from Mars Global Surveyor reveal the topography of Mars better than many continental regions on Earth. May 27, 1999 NASA NASA Science News Search for life on Mars will start in Siberia -- Russian and NASA scientists will look for life forms in the inhospitable realm of Siberian permafrost. May 27, 1999 NASA NASA Science News Stormy weather on Mars -- During the recent close approach of Mars to Earth, NASA's Hubble Space Telescope spotted a gigantic storm swirling near the Red Planet's north pole. May 19, 1999 NASA NASA Science News Mars unveils a magnetic personality -- Plate tectonics on the Red Planet might have important consequences for ancient Martian life. Apr 30, 1999 NASA NASA Science News Plate tectonics on Mars? -- Magnetic stripes on the surface of Mars are similar to fields in the sea floors of Earth. Apr 29, 1999 NASA NASA Science News A close encounter with the Red Planet -- Mars makes its closest approach to Earth in 1999. Apr 23, 1999 NASA NASA Science News A new face on Mars has scientists smiling -- MGS beams back pictures of the "Happy Face Crater". Mar. 12, 1999 NASA NASA Science News Related Web Links: Gusev Crater and Ma'adim Vallis -- Global Surveyor images Mars weather, climate, and life FAQ -- from NASA/Ames www.MonoLake.org -- Mono Lake home page What would happen to a dead body on Mars? -- NASA/Ames Quest Ask-a-Scientist query Mars Surveyor 2001 -- home page at JPL Mars Global Surveyor -- home page at JPL THEMIS -- Thermal Emission Imaging System from ASU ASU Planetary Exploration Lab -- Thermal Emission Imaging System from ASU NASA Astrobiology -- an excellent website from NASA/Ames |
![]() Appendix: Where did all the water go?There may have once been ponds and lakes on Mars, but they're dry now. Physical conditions on the surface of Mars, namely low atmospheric pressure and low temperature, conspire to make liquid water unstable. The average atmospheric pressure on Mars is only about 6 millibars compared to the Earth's average pressure of 1013 millibars. The average surface temperature on Mars is about -60 deg C compared to the Earth's 15 deg C. At certain locations and times on Mars, when the air pressure is high enough and the temperature is above freezing (greater than 0 deg C), liquid water is theoretically possible; but the rate of evaporation would be so great that liquid water (if it were present) would rapidly vaporize.Nevertheless, there is widespread evidence of dried-up valleys and channels thought to have been eroded by liquid water. Many Martian outflow channels strongly resemble flood channels on Eath, like those in eastern Washington in the USA. On Mars they may have formed when groundwater or subsurface slush was catastrophically brought to the surface, perhaps triggered by large impacts or "marsquakes". On the other hand, geological studies of the valley networks suggest that these must have been gradually eroded by running water: some show morphology suggesting formation by groundwater sapping (i.e. when a river is fed by a spring and the valley grows by headward erosion); others seem to have been produced by precipitation runoff. The valley networks are almost completely (but not quite) restricted to ancient upper highlands, dated as 3.5 to 4.0 billion years old from the quantity of impact craters, so it is postulated that environmental conditions on Mars must have been conducive to liquid water at this time. ![]() The upper limit on the present amount of water on the martian surface is 800,000 to 1.2 million cubic miles (3.2 to 4.7 million cubic kilometers), or about 1.5 times the amount of ice covering Greenland. If both caps are composed completely of water, the combined volumes are equivalent to a global layer 66 to 100 feet (22 to 33 meters) deep, about one-third the minimum volume of a proposed ancient ocean on Mars. |
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