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Can Liquid Water Exist On Present-Day Mars
Cambridge - Jan. 24, 2001 In 1998, NASA's Associate Administrator Wesley Huntress, Jr., stated, "Wherever liquid water and chemical energy are found, there is life. There is no exception." Could there, then, be life on Mars? In the mid-1970s, the Viking Lander mission's Gas Exchange Experiment detected strong chemical activity in the martian soil. Liquid water seems to be the one element needed for the equation of life on Mars. The presence of water there, however, is still hotly contested. Many scientists believe that liquid water does not and cannot exist on the surface of Mars today. Although surface water may have been plentiful in Mars' past, they say, the current conditions of freezing temperatures and a thin atmosphere mean that any water on Mars would have to be deep underground. Moreover, if any water ice existing on Mars were somehow warmed, it still wouldn't melt into water. The thin martian atmosphere instead would cause the ice to sublime directly into water vapor. But Dr. Gilbert Levin of Spherix, Inc., and his son, Dr. Ron Levin of MIT's Lincoln Laboratory, believe differently. They say that liquid water-in limited amounts and for limited times-can exist on the surface of present-day Mars. They have based their theory on data collected from the Viking landers and on the 1997 Mars Pathfinder mission. This father-son team has suggested a diurnal water cycle on Mars: water vapor in the air freezes out by night, then during the day the ice melts. As the day progresses, the heat of the Sun causes this liquid water to evaporate back into the air.
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