Curiosity Finds a Strange Honeycomb Pattern of Cracks on Mars

NASA's Curiosity rover has photographed a Martian landscape covered in small, honeycomb-like cracks, a polygon pattern the car-sized rover has not examined up close before. The fractures, each polygon measuring about 4 to 8 centimetres (1.5 to 3 inches) across, appear in Gale Crater, the region Curiosity has been exploring since it landed on Mars.

Scientists hypothesise that similar polygon cracks in Gale Crater form as mud cracks, a process discussed in a 2023 study in the journal Nature. That study proposed the cracks could date to the Noachian-Hesperian transition, a period roughly 3.8 to 3.6 billion years ago when Mars may have had an Earth-like climate with repeated wet-dry cycles. Researchers behind the newly photographed polygons say more work is needed to confirm exactly how these particular ones formed.

"We've seen a lot of fascinating landscapes through Curiosity's eyes, but this sea of polygons took our breath away," said Ashwin Vasavada, a Curiosity mission scientist at NASA's Jet Propulsion Laboratory. "We measured their shapes and chemistry carefully and are hopeful there are clues in the data as to how these features formed."

Polygon patterns have been spotted elsewhere on Mars too, both at ground level and by NASA's High-Resolution Imaging Science Experiment (HiRISE) orbiter, which has circled the planet since 2006. But those larger orbiter-imaged polygons, seen in regions such as Hellas Planitia, Noachis Terra and Margaritifer Terra, range from 15 to more than 350 metres across, and are hypothesised to have formed instead from freeze-thaw cycles or tectonic and volcanic stress, not mud cracking. Gale Crater remains the only place where mud-crack-like polygons have been examined at ground level by a rover.