Curiosity Rover Spots a Field of Small Polygon Cracks on Mars for the First Time

NASA's Curiosity rover has photographed a wide field of small polygon-shaped cracks in Gale Crater on Mars. Similar patterns have been spotted elsewhere on Mars by orbiters, but this is the first time the car-sized rover has observed this type of landscape up close.

The polygons measure about 4 to 8 centimeters (1.5 to 3 inches) across. Scientists hypothesize they formed as mud cracks during repeated wet-dry cycles. A 2023 study in the journal Nature linked similar cracks in Gale Crater to the Noachian-Hesperian transition, a period about 3.8 to 3.6 billion years ago when Mars may have had an Earth-like climate. Researchers studying the newly observed polygons say more work is needed to confirm how they 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-shaped surface features have been photographed elsewhere on Mars by NASA's High Resolution Imaging Science Experiment (HiRISE) orbiter, but those polygons are much larger, ranging from about 15 to more than 350 meters (50 to more than 1,000 feet) across. Some of the larger orbiter-imaged polygons, found in regions such as Hellas Planitia, Noachis Terra and Margaritifer Terra, may point to past standing water. Ground-level rover observations of such features have so far been limited to Gale Crater.

Mars today is cold and dry, but its surface still preserves processes that may date back 4.5 to 3.0 billion years, spanning the Pre-Noachian, Noachian and Hesperian periods.