Summary
NASA’s Curiosity rover has discovered an unusually extensive field of polygonal fractures in a Martian valley. Scientists are studying whether the honeycomb-like patterns formed through drying, temperature changes or processes that compressed ancient sediments.
NASA’s Curiosity rover has photographed the largest concentration of honeycomb-like surface patterns the mission has encountered on Mars. The features, called polygonal fractures, cover the terrain around a small, sand-capped butte in a valley known as “Valle Grande.”
Each polygon is about 1.5 to 3 inches (4 to 8 centimetres) across. In a 360-degree panorama captured on June 19 and 20, 2026—the mission’s 4,930th and 4,931st Martian days—the patterns extend in every direction as far as the rover can see. They also continue around the sides of “Miraflores,” a nearby butte estimated to be 20 feet (6 metres) high.
A geological pattern on an unusual scale
Polygonal fractures are cracks that divide a surface into many-sided shapes. On Earth, similar patterns can form when wet sediment dries and contracts, but polygonal textures can also result from other physical processes. NASA says some of the polygons previously observed by Curiosity clearly formed as mud cracks. For the newly discovered field, the formation process has not yet been determined.
Other possibilities include repeated warming and cooling, which can cause material to expand and contract, or compression that forces water out of sediment as it is buried. The shape alone therefore provides a starting point for geological analysis rather than a complete explanation of the terrain’s history.
Curiosity’s instruments are examining the polygons’ shapes and chemistry. Mission scientists hope those measurements will help distinguish between the possible processes and reveal whether the fractured surface records a particular episode in Mars’ environmental history.
What Curiosity is investigating
The rover encountered the field while beginning an ascent through Valle Grande on the lower slopes of Mount Sharp, a mountain roughly 3 miles (5 kilometres) tall. Curiosity has been climbing Mount Sharp since 2014, investigating layers of rock and sediment that formed during a period when lakes and streams were present in the region.
That setting makes the new textures useful beyond their striking appearance. If the polygons formed in mud, they could preserve evidence of wet sediment that later dried. If temperature cycles or burial-related compression played the larger role, the features would record a different sequence of physical changes. Their chemistry and relationship to nearby rocks may help determine which interpretation fits the site.
The discovery adds to a long record of geological observations made by Curiosity since its landing on Mars on Aug. 5, 2012. The rover has previously examined sulfur crystals, meteorites and sedimentary rocks, as well as chemical evidence from Mars’ wetter ancient past.
NASA says Curiosity has found carbon-based molecules that are believed to be precursors to RNA and DNA. Those molecules can be produced by biological or geological processes, so their presence is evidence of suitable ancient chemistry rather than evidence that life existed there. The polygon field contributes a separate line of geological evidence about the conditions that shaped the Martian surface.
For now, the main significance of the site is its scale: mission scientists have not previously seen so many of these many-sided features together in one place. Further analysis of the rover’s images and chemical measurements will determine whether the field records drying mud, environmental temperature changes, sediment burial, or a combination of processes.