Curiosity Found Rock Layers Left by an Ancient Sandstorm on Mars. What Does That Tell Us?
NASA's Curiosity rover photographed a rock in Gale crater that researchers say records one ancient Martian sandstorm. The study was the cover paper of the July 1, 2026 issue of the journal Geology, led by Steven Banham of Imperial College London, as summarised by OrbitalHub on October 3, 2026.
What the rover saw
On December 12, 2024 (its 4,391st Martian day), Curiosity imaged a rock nicknamed "Jawbone Canyon" in the Mirador formation on the lower slopes of Mount Sharp. Inside are layers only millimetres thick, called supercritical climbing wind ripple strata. The rock is about a metre wide and 20 cm high, with six stacked packages of these layers.
Why climbing ripples matter
Normally, wind-blown ripples migrate downwind without growing taller. When wind is strong and sand is plentiful, sand piles up faster than the ripple moves, so the ripple "climbs". The team measured climb angles of 10 to 18 degrees, which the paper says need storms lasting minutes to hours, not slow seasonal winds. The authors write that the layers suggest "a broader sustained event, such as a sandstorm or gale, lasting several hours or more."
What it suggests about early Mars
Mars today has an atmosphere of roughly 6 millibars at the surface, which the researchers say is too thin to move sand at this scale. So the air about 3.6 billion years ago was probably denser than now. How much denser is not pinned down.
A caution
The "first direct evidence" claim comes from the research team and its reporting. A second summary article we checked (Smart Data Week) is general and adds little detail, so the numbers above rest mainly on the OrbitalHub summary of the Geology paper (DOI 10.1130/G54158.1). We did not read the paper itself.
Sources
- OrbitalHub, "Curiosity just found the first physical proof that sandstorms once ripped across Mars", October 3, 2026: https://orbitalhub.com/2026/10/03/curiosity-just-found-the-first-physical-proof-that-sandstorms-once-ripped-across-mars/
- Smart Data Week, "Ancient Mars Sandstorm Wreckage Discovered by Curiosity Rover", October 2, 2026: https://smartdataweek.com/article/ancient-mars-sandstorm-wreckage-discovered-by-curiosity-rover-space-exploration-2026
Facts checked: October 4, 2026.