Curiosity’s One-Centimeter Footprints on Mount Sharp

Fourteen years after touching down in Gale Crater, Curiosity is still finding surface details that stop its science team mid-plan. In mid-August 2026, during sols 4988 through 4994, the rover paused among layered rocks on the lower slopes of Mount Sharp and photographed a scatter of broad, shallow pits cut into bedrock. One of them, captured by the Mars Hand Lens Imager on the end of the robotic arm on sol 4989, measures about a centimeter across and, from certain angles, looks uncomfortably like a small footprint.

Michelle Minitti, the deputy lead investigator on that up-close camera, stated that both work sites that week encountered features that were unlike anything the mission had observed before. You know, ordinary pits appear all across Mars. Weathered rock and other debris simply disintegrates, leaving a gap and a smattering of residual pebbles. These new depressions were much larger and flatter than the ones we’d seen before, and there was no indication of what had caused them to disappear. There is no calling card from the mystery burrower.

Curiosity basically brought out the big guns to solve the mystery. MAHLI and Mastcam captured images, stereo mosaics, and tight, overlapping frames, allowing the crew to create a very detailed image of each pit’s walls and floor, while ChemCam fired its laser and took remote shots. The chemistry was verified using an Alpha Particle X-Ray Spectrometer. We’re already seeing some fascinating effects, with distinct layers of material inside the pit that don’t quite match the surrounding rock. That is our first real hint.

Mount Sharp is a five-kilometer-high stack of sedimentary rock located in the center of Gale Crater. It is essentially a record of old lakes, rivers, and eventually dry winds. Curiosity has been gently climbing those layers for years, analyzing all the changes in particle size, mineralogy, and color, similar to a geologist exploring the canyon wall on Earth. The pits appeared in Valle Grande, which also features buttes named Cordillera, Tolhuaca, and Potosí. The cross bedding and dark cap material on the buttes already indicated that the circumstances had shifted at some point. The pits merely add to the puzzle, making it much more hard.

No one on the team is treating the shapes as tracks left by an animal. Impact craters of this size and shallowness do not fit either. Wind abrasion, late-stage fluids moving through the rock, or some combination of weathering the rover has not catalogued yet remain on the table. The absence of the usual leftover pebbles is what makes the geometry hard to dismiss as just another nodule hole. Minitti called the bedrock anything but boring and labeled the pits a welcome new puzzle in the stratigraphy. That is scientist language for “we do not have the answer yet, and that is the interesting part.”