November 29, 2011
For today’s Cool Photo of the Week, Seymour Simon chose this photograph taken by NASA’s Mars Reconnaissance Orbiter, an unmanned satellite that has been orbiting the Red Planet since 2005. The orbiter is searching for evidence that water was once present on the surface of Mars. NASA scientists also want to know whether water was present long enough to support life at some time in the past.
Look at the deep ditches and trails criss-crossing the sand dunes in an area of Mars known as the Russell Crater. These trails were carved into the landscape by "dust devils," mini-tornadoes that whip across the Martian landscape. The ditches are formed when chunks of frozen carbon dioxide slide down the face of steep dunes.
When I speak at schools, I often tell students about an astronomer named Percival Lowell, who thought he spotted Martian "canals" through his small telescope back in the early 1900s. Do you think it’s possible that he saw these deep trails, leading him to the mistaken idea that the canals must have been dug by intelligent life, or Martians?!
Posted by: Seymour Simon
