The layering of the lamellar rocks, captured with the mast camera, suggests they formed in the bed of a small pond or stream. They were discovered as Curiosity moved from a clay-rich area at the base of a mountain called Mount Sharp to a sulfate-rich area at the summit. As the rover ascends the mountain, the types of rocks it sees are changing — less evidence of lakes and more of creeks.
Ashwin Vasavada, Curiosity project scientist, said: “We no longer see the lake deposits that we have seen under Mount Sharp for years. Instead, we see a lot of evidence of dry climates, such as dry sand dunes with occasional streams surrounding them. “This is a big change from previous lakes that may have lasted for millions of years.”
Curiosity landed on Mars on August 5, 2012, and is about to celebrate its 10th birthday. Despite the harsh environment on Mars, including low temperatures, sharp rocks and dust storms, its hardware is still going strong. However, the rover did encounter an issue recently that caused it to go into safe mode for several days. NASA announced that the high temperature was recorded in an instrument control box inside Curiosity, and the safety mode was automatically activated to prevent any damage caused by an unknown problem.
Engineers aren’t sure what caused the problem, but they believe it may be a faulty sensor reading rather than an actual problem with the rover’s hardware. Curiosity quickly resumed its science operations and was able to collect data from its various instruments as usual. One long-standing problem with the rover’s hardware, though, is wear on its wheels. During the rover’s ten years on the road, the rover’s wheels have been damaged by sharp rocks on the Martian surface, with holes and tears in their treads, called grousers. The rovers can still be maneuvered as usual, but the team is careful with how they drive to minimize damage.
“We’ve proven through ground testing that we can safely drive on the rim if necessary,” said Curiosity project manager Megan Lin at NASA’s Jet Propulsion Laboratory. “If we one day get to the point where most of the lattice of a wheel is broken, we can do a controlled break to discard the remaining pieces. Because of recent trends, it seems unlikely that we will need to take this action. The wheels held up well and gave us the traction we needed to keep climbing.”
