Daffodil International University
Faculty of Engineering => EEE => Topic started by: Kazi Taufiqur Rahman on November 23, 2015, 11:54:53 PM
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New data suggest that during parts of the year, water flows on Mars. Studies have found evidence that this Red Planet once had plenty of water — and that surface moisture or ice might still remain. But there was no evidence of actual flowing water. Until now.
And even now, that evidence is still indirect.
For some time, scientists have witnessed seasonal dark streaks. They appear etched onto some slopes of the Martian surface. They form each year during the Martian summer, then disappear as winter approaches. A new study has now analyzed light spectra at four of these streak sites. Scientists used a spectrometer (Spek-TROM-eh-tur). It analyzes light reflected off of the Martian surface to gauge the minerals present. The instrument is flying aboard the Mars Reconnaissance Orbiter, a satellite.
Those seasonal dark streaks are hydrated salts. Or that’s the conclusion of a new report. The compounds appear to be magnesium perchlorate, magnesium chlorate and sodium perchlorate. Each salt is a type that normally needs liquid water to form. So scientists believe liquid water must be flowing down the slopes. Along the way, it appears to be depositing the salty residues.
The salt trails show up only in warm seasons. Rising temperatures probably drive water to the surface, the scientists say. Still unclear is the source of that water. It could be buried ice, underground pools or something else. The new report appeared online September 28 in Nature Geoscience.
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Thanks for sharing