Weird Spirals Spotted on Mars
May 4, 2012
Strange spirals discovered on the surface of Mars strongly suggest that fire, not ice, was responsible for the formation of a region that has puzzled scientists for more than a decade. The spirals–rock formations that look like coils of rope–were discovered by graduate student Andrew Ryan of Arizona State University in images of Athabasca Valles, a network of valleys near the Martian equator. The images were made by a high-resolution camera aboard NASA‘s Mars Reconnaissance Orbiter that can provide clear images of objects about the size of a beach ball at a distance of 185 miles (300 kilometers).
Athabasca Valles is a network of valleys about 185 miles long near the Martian equator. The region’s surface is covered by huge plates that have cracked and broken into thousands of irregularly shaped, multisided blocks. Ryan and his co-author Philip Christensen reported finding 269 spirals, ranging in diameter from 16 to 98 feet (5 to 30 meters), between the blocks.
Some scientists have argued that the blocks in Athabasca Valles, which look like Arctic ice floes, formed as sheets of ice moved across the Martian surface. Others argued that the cracks formed because of volcanic activity. Mars has the largest volcanoes in the solar system, including gigantic Olympus Mons. Ryan and Christensen contend that the spirals provide strong evidence for the lava theory. They note that similar features can be seen in the smooth, slow-moving lava flows on Hawaii. There, the rubbery surface of the flows is twisted into coils as the liquid lava streams below move in different directions at different speeds. They argue that a similar process must have produced the spirals in Athabasca Valles. Some scientists, however, continue to argue that ice was responsible for the blocks in the region.
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