News Archive

Friday, October 29, 2004 Severe Glaciation Responsible for Underground Ice People walking on a glacier. Credit: Unknown For a long time, the distribution of ice on Mars has puzzled scientists. The prevailing theory involved sublimation from the regolith and distribution to the higher latitudes through the atmosphere, but the Martian regolith simply can't hold the amount of ice required to explain it. Now scientists at the Observatoire de Paris have come up with an answer. Mars has been long known to undergo severe changes in the obliquity of its orbit. As on Earth, this tilting changes the amount of sunlight that each portion of Mars receives, which causes ice ages much more powerful than those found on Earth. During the periods of highest tilt, the northern polar cap evaporates, moving the ice to the colder areas around Tharsis on the equator. Then, when the tilt becomes smaller, the Tharsis ice evaporates and becomes deposited not only just on the polar caps, but also in a wide region of high latitudes. This accounts perfectly for what we've observed so far: high concentrations of ice underground near the high latitudes, and remnant ice on Tharsis. Now that we better understand the process by which water moves around Mars, it will be easier to understand where best to find water. This will help greatly in the exploration and colonization of Mars. (More info: SpaceRef.com) @ 16:40 EST