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|Vast Oceans Once Covered Mars|
(CNN) - Mars is now dry, dusty and cold, but a new study confirms that the Red Planet once was covered by vast oceans and had more water per square mile than Earth. In fact, it once had enough water to cover the planet to a depth of almost a mile, researchers say, citing an analysis of data measuring the amount of molecular hydrogen in the atmosphere. Unlike Earth, Mars lost its water over millions of years through a combination of chemical reaction and the bombardment of asteroids and comets. There is much evidence now that Mars had an ocean of liquid water, said Vladimir A. Krasnopolsky of Catholic University of America. "But the climate changed. ... Mars became a cold desert." In a study appearing Friday in the journal Science, planetary researchers Krasnopolsky and Paul D. Feldman of Johns Hopkins University said that Mars' upper atmosphere contains molecular hydrogen, or H2, a finding that confirms earlier theoretical models of the water history of the planet. The H2 comes from a chemical reaction, called dissociation, that split the hydrogen from water, H20, and allowed the lighter hydrogen to escape to the atmosphere.
(More info: CNN.com)
- posted by Alex @ 19:59 EST