Curiosity provides first close-up views of Martian sand dunes
NASA’s Curiosity Mars Science Laboratory (MSL) rover is currently in the midst of the first close-up investigations of sand dunes on a planet other than Earth. The rover recently drove around “Namib Dune” – which stands approximately 13 feet high (4 meters) – to observe its face.
Scientists are using Curiosity to investigates the Bagnold Dunes, a band of dark sand dunes that line the southwestern flank of Mt. Sharp – the layered mountain within Gale Crater that Curiosity is climbing.
One trait that sets true dunes apart from other wind-shaped bodies of sand such as ripples and drifts is a steep, downwind slope called a slip face. At this spot, sand blowing across the windward side of the dune suddenly becomes sheltered from the wind by the dune itself. The sand falls from the air and accumulates on the slope until it becomes steepened and flows down the face of the dune in the form of mini-avalanches.
Curiosity’s campaign of investigating the Bagnold Dunes is designed to increase our understanding of how wind moves and sorts grains of sand in an environment with less gravity and less atmosphere than the dune-fields of Earth. The Bagnold Dunes are active. Images taken from orbit show that this region is migrating by as much as 3 feet (about 1 meter) per Earth year.
“We’ve planned investigations that will not only tell us about modern dune activity on Mars but will also help us interpret the composition of sandstone layers made from dunes that turned into rock long ago,” said Bethany Ehlmann of the California Institute of Technology and NASA’s Jet Propulsion Laboratory, both located in Pasadena, California.
While Curiosity has not caught a sand-slide in action, images taken of the Namib Dune slip face appear to indicate where such slides have recently occurred. The Bagnold Dunes are probably most active in Mars’ southern summer, rather than the current late-fall season. In the meantime, the one-ton robotic explorer has made steady progress in its scientific exploration of Gale Crater.
Curiosity began its investigations of the Bagnold Dunes in early December. A few days of rover operations during that month were affected by an arm-motion-fault. This was diagnosed as being due to a minor software issue and normal operations of the arm resumed on Dec. 23.
On Jan. 4, Curiosity used its MAHLI camera to check the condition of its wheels. The nuclear-powered rover began driving the following day to a new location that will allow easier access for sampling part of Namib Dune.
Curiosity touched down on the surface of Mars in August of 2012, since that time it has been moving toward Mount Sharp. Initially given a planned two-year mission life, the success of the mission has warranted an indefinite extension.
Video courtesy of NASA
Jim Sharkey is a lab assistant, writer and general science enthusiast who grew up in Enid, Oklahoma, the hometown of Skylab and Shuttle astronaut Owen K. Garriott. As a young Star Trek fan he participated in the letter-writing campaign which resulted in the space shuttle prototype being named Enterprise. While his academic studies have ranged from psychology and archaeology to biology, he has never lost his passion for space exploration. Jim began blogging about science, science fiction and futurism in 2004. Jim resides in the San Francisco Bay area and has attended NASA Socials for the Mars Science Laboratory Curiosity rover landing and the NASA LADEE lunar orbiter launch.