A venerable Red Planet rover could spot signs of the Martian climate drying up in ancient times.
NASA’s long-running Curiosity mission, which will reach its 10th Earth year anniversary on the Red Planet in August, is ascending the slopes of Mount Sharp (Aeolis Mons) to track how Mars’ climate has changed over the eons . During the last year or so of its roaming, Curiosity noticed the water-rich clay giving way to a transition zone filled with salty sulfate. Scientists currently believe these features mark where streams dried up and sand dunes formed, according to a NASA statement. (opens in a new tab).
This means that the lake deposits that populated the lower slopes are not as common as Curiosity reaches further up the mountain. “Instead, we see plenty of evidence of drier climates, such as dry dunes that were sometimes surrounded by streams,” Ashwin Vasavada, Curiosity project scientist at JPL, said in the statement.
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In addition to more sulphate, geological features are attracting the attention of scientists. They see sediment likely deposited in stacks of “flaky layers”, including one dubbed “The Prow” by team members.
The area has a complex history, including a dry origin story as an area filled with sand dunes and some areas that appear to have had water-borne sediment, JPL said.
“Making the story richer even more complicated is knowing that there were multiple periods in which groundwater flowed and ebbed over time, leaving a jumble of puzzle pieces for Curiosity scientists to piece together. in a precise timeline,” the officials added in the statement.
While the rover is still performing well, JPL noted that it is showing inevitable signs of age, including holes in its aluminum wheels that have been navigating Martian terrain since Curiosity landed on August 5, 2012.
The left center wheel, as seen in images taken on June 2 this year, has more damage and gaps in its lugs (treads). JPL said the studs are unlikely to completely disintegrate, but ground tests have shown that at worst the rover can roll over its wheel rims if necessary.
Curiosity also had a brief crash in safe mode on June 7 after an unexpected temperature spike on an instrument control box. The rover exited safe mode two days on Earth later, and team members are investigating the cause.
“They suspect safe mode was triggered after a temperature sensor provided an inaccurate reading, and there is no indication that this will significantly affect rover operations, as backup temperature sensors can ensure that the electronics inside the rover’s body don’t get too hot,” JPL said.