September 24, 2013
NASA’s Curiosity Resumes Journey After Short ‘Darwin’ Site Visit
Lee Rannals for redOrbit.com - Your Universe OnlineDarwin" is where the rover used instruments to inspect rocks. NASA said this pit stop paid off with the investigation of targets that bear evidence of ancient wet environments.
"We examined pebbly sandstone deposited by water flowing over the surface, and veins or fractures in the rock," said Dawn Sumner of University of California, Davis, a Curiosity science team member with a leadership role in planning the stop. "We know the veins are younger than the sandstone because they cut through it, but they appear to be filled with grains like the sandstone."
Darwin sits about one-fifth of the way along the route towards Mount Sharp, which is the mission's main destination. Curiosity's science team has planned a few waypoints to collect information about the geology between Glenelg and Mount Sharp. They hope to understand the relationship between what the mission already discovered at Glenelg and what it might find at Mount Sharp.
"We want to understand the history of water in Gale Crater," Sumner said. "Did the water flow that deposited the pebbly sandstone at Waypoint 1 occur at about the same time as the water flow at Yellowknife Bay? If the same fluid flow produced the veins here and the veins at Yellowknife Bay, you would expect the veins to have the same composition. We see that the veins are different, so we know the history is complicated. We use these observations to piece together the long-term history."
The top priority for the "Darwin" stop was to examine a conglomerate rock outcrop, such as the pebbly sandstone.
"As often happens, the closer we get, the more is revealed," said Kenneth Williford of NASA's Jet Propulsion Laboratory, Pasadena, California.
Scientists selected Waypoint 1 because images taken nearly 100 yards away showed outcrops that looked like conglomerate. At Darwin, Curiosity used two instruments mounted on the arm, including the Alpha Particle X-ray Spectrometer and the Mars Hand Lens Imager. The rover examined eight targets at the waypoint using the spectrometer and camera on the arm.
"There's a trade-off," Williford said, "between wanting to reach Mount Sharp as soon as we can and wanting to chew on rocks all along the way. Our team of more than 450 scientists has set the priority on getting to Mount Sharp, with these few brief waypoint stops."