Was there water on Mars, this question has always been perplexing. Mysterious lines on Mars may be the result of dry ice, scientists have concluded
The mystery behind the lines on the Red Planet that baffled the scientists for many years has finally been solved. By closely examining the images from NASA’s Mars Reconnaissance Orbiter (MRO) and performing experiments on sand dunes in Utah and California, the scientists from NASA were able to conclude that the linear shapes were the result of dry ice gliding down the slopes.
What generated the curiosity about the mile-long channels discovered on Mars that were first found in 2002 was the fact that unlike similar lines found on Earth that ended in debris as as the rolling material got deposited at the bottom, the one on Mars abruptly end in a pit. To solve the mystery behind these furrows, the researchers’ alongwith examining the images also performed experiments on sand dunes in Utah and California, where they dropped frozen carbon dioxide and dry ice blocks down the dunes to see what would happen. The frozen carbon dioxide slid down the dunes on what scientists describe as “cushions on gas similar to miniature hovercraft.” The block easily glided over both steeper and flatter dunes, leaving a shallow carving in its wake.
Speaking about the discovery, Serina Diniega, a planetary scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California and lead author of a report published online by the journal Icarus, said; “In debris flows, you have water carrying sediment downhill, and the material eroded from the top is carried to the bottom and deposited as a fan-shaped apron. In the linear gullies, you’re not transporting material. You’re carving out a groove, pushing material to the sides. I’m looking forward to the day when astronauts can engage in a whole new area of extreme sports. They could snowboard down these carbon dioxide-covered dunes on a cushion of carbon dioxide. They would just shoot right down those slopes. It would be amazing.”
The hillside grooves that were found on Mars, called linear gullies, revealed relatively constant width up to a few yards, or meters, across with raised banks or levees along the sides having pits at the downhill end.
Diniega said: “In debris flows, you have water carrying sediment downhill, and the material eroded from the top is carried to the bottom and deposited as a fan-shaped apron. In the linear gullies, you’re not transporting material. You’re carving out a groove, pushing material to the sides.”
Images from MRO’s High Resolution Imaging Science Experiment (HiRISE) camera show sand dunes with linear gullies covered by carbon-dioxide frost during the Martian winter. The location of the linear gullies is on dunes that spend the Martian winter covered by carbon-dioxide frost. By comparing before-and-after images from different seasons, researchers determined that the grooves are formed during early spring. Some images have even caught bright objects in the gullies.
“Linear gullies don’t look like gullies on Earth or other gullies on Mars, and this process wouldn’t happen on Earth.
You don’t get blocks of dry ice on Earth unless you go buy them,” said Diniega.
Source : http://nvonews.com/2013/06/13/water-on-mars-mysterious-lines-on-mars-result-of-dry-ice/