AI Insight
NASA's Curiosity rover discovered unusual broad, shallow pits in Martian bedrock during sols 4988-4994, unlike features previously observed in its 14-year mission. The rover's instruments (MAHLI, Mastcam, ChemCam, and APXS) documented these pits and analyzed complex layered bedrock showing evidence of changing depositional conditions on Mount Sharp. The science team also monitored a potential regional dust storm that appeared to dissipate by week's end.
Why it matters
These unusual geological features provide new insights into weathering processes and environmental conditions in Mars' geological history. Understanding the formation mechanisms of these pits and the stratigraphic variations could help reconstruct past Martian surface conditions and inform future exploration strategies.
Understand the Science
2 min read
Curiosity Blog, Sols 4988-4994: More New Tricks for an Old Dog

Written by Michelle Minitti, MAHLI Deputy Principal Investigator
Earth planning date: Friday, Aug. 21, 2026
After Curiosity’s 14 years on the surface, Mars continues to surprise. Both of our workspaces this week contained features unlike quite anything we have seen in the past — broad, shallow pits (like the one in the image above) dotted across the bedrock. Pits are not uncommon — when resistant nodules or pebbles weather out of their host rock, they leave behind a void. But the pits of this week were much broader and shallower than past features and were not accompanied by obvious objects that were once in the pits. MAHLI and Mastcam were particularly interested in these features, acquiring stereo mosaics of them and tightly overlapping image sets that can be turned into a digital elevation model of their structure. They were a welcome new puzzle into the processes that have affected this particular section of rocks in the stratigraphy of Mount Sharp.
The “typical” bedrock was anything but boring. Mastcam imaged and ChemCam rastered across complex packages of layers with changes in texture and structure over short vertical differences. These might be evidence of changes in depositional conditions captured in close proximity to one another. ChemCam, MAHLI, and APXS analyzed gray, rough, resistant layers that differed from the host bedrock, likely indicative of a different chemistry. ChemCam studied one of the gray float rocks (like the small, loose pebble in the image above) that have been scattered variably across our workspaces, to try to understand the origins of these stones. Farther afield, the “Cordillera” butte continued to garner attention, with a comprehensive Mastcam mosaic covering its entire visible face, and more focused ChemCam RMI mosaics aimed at specific horizons. The “Tolhuaca” and “Potosí” buttes, which are farther south down “Valle Grande,” were also targets, with ChemCam looking for potential crossbedding and assessing the mineralogy of dark material capping Potosí.
Our environmental science team members were just as busy, planning REMS, Mastcam, and Navcam activities at a higher-than-usual cadence to monitor a potential regional dust storm. They found by the end of the week, however, that the storm appeared to be dissipating.
We managed to accomplish all of this despite having lost one of our planning days due to a lost downlink.

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Source: Curiosity Blog, Sols 4988-4994: More New Tricks for an Old Dog





