NASA’s Curiosity rover honeycomb landscape discovery in a Martian valley known as Valle Grande has revealed a sweeping field of polygonal fractures, with individual patterns measuring roughly 1.5 to 3 inches, or 4 to 8 centimeters, across.
Curiosity has documented smaller groupings of similar geometric features before, but nothing on the scale now visible in Valle Grande.
A sea of polygons across Mars
A 360-degree panorama taken on June 19 and 20, during the mission’s 4,930th and 4,931st Martian days, or sols, shows the patterns extending in all directions as far as the rover can see.
The formations also ascend the sides of a nearby butte nicknamed Miraflores. The outcrop rises about 20 feet, or 6 meters, above the surrounding terrain and is topped by a thick sand layer.
“We’ve seen a lot of fascinating landscapes through Curiosity’s eyes, but this sea of polygons took our breath away,” said project scientist Ashwin Vasavada of NASA’s Jet Propulsion Laboratory in Southern California. “We measured their shapes and chemistry carefully and are hopeful there are clues in the data as to how these features formed.”
What created the honeycomb patterns?
Some polygonal networks examined earlier by the rover likely began as cracks in drying mud. Scientists note that several processes can produce this honeycomb appearance.
Thermal cycling, repeated warming and cooling, can fracture the surface into geometric shapes. Compression can generate similar patterns by expelling water from sediment after it becomes buried.
Researchers are now assessing the newly observed field to determine which of these mechanisms, or a combination of them, shaped the Valle Grande terrain.
Fourteen years of Martian surprises
The expansive polygon field is the latest in a series of unexpected observations since Curiosity touched down on Aug. 5, 2012, 14 years ago.
Along its route, the rover has encountered sulfur crystals, reflective meteorites, and other unusual geologic textures. More broadly, the mission has reshaped understanding of ancient Mars by showing that the planet once hosted water, favorable chemistry, and nutrients that could have supported microbial life.
Evidence of Mars’ watery past
Billions of years ago, lakes and streams dotted the lower flanks of Mount Sharp, a 3-mile-tall, or 5-kilometer-tall, mountain that Curiosity has been climbing since 2014.
The rover has identified chemical traces from that wetter era, including carbon-based molecules regarded as possible precursors to RNA and DNA, nucleic acids that carry genetic information.
Available data do not indicate whether those organics formed through biological or geological processes. Both remain plausible. Even so, the finding reinforced that ancient Mars contained the necessary chemical ingredients for life.
Managed by Caltech in Pasadena, JPL built Curiosity and leads the mission for NASA’s Science Mission Directorate in Washington as part of the agency’s Mars Exploration Program.
NASA’s Curiosity rover continues operations overseen by Jet Propulsion Laboratory, while cultural reflections on the mission include works such as the Curiosity rover poem imagines a postcard from Mars.