A Sea of Tiny Honeycomb Cracks on Mars Could Show How Water Hold Clues to Ancient Water

For years, NASA’s Curiosity rover has been climbing Mount Sharp, the enormous mountain rising from the center of Mars’ Gale Crater. Along the way, it’s explored ancient lake deposits, water-altered minerals, and organic compounds preserved in Martian rock.

Now it has reached something unlike any landscape it has encountered at this scale before.

A vast network of tiny polygonal ridges covers the ground around the rover, creating what looks like a stone honeycomb stretching toward the horizon. Curiosity has seen similar patterns before, but only in smaller patches. This field appears to cover an entire band of terrain near a channel called Valle Grande.

“We’ve seen a lot of fascinating landscapes through Curiosity’s eyes, but this sea of polygons took our breath away,” Ashwin Vasavada, a scientist at NASA’s Jet Propulsion Laboratory, said.

This unusual discovery could help researchers know how long water remained on its surface and whether the planet’s climate was stable enough for life to emerge.

A giant puzzle etched into the Martian surface

Polygon-shaped fractures aren’t unique to Mars. They can form when wet mud dries and contracts, when repeated temperature swings make the ground expand and shrink, or when buried sediment is compressed and loses water.

That can make some of Curiosity’s observations difficult to interpret. A small patch may offer only a handful of fractures, leaving scientists with too little information to distinguish one formation process from another.

The newly discovered area brings new answers. Researchers can now compare the dimensions, shapes and chemistry of polygons spread across a continuous area. They can also examine whether the ridges and their centers contain different minerals.

Curiosity first got a close look at the field in June 2026 after driving into an area that appeared smooth in orbital images. From the ground, however, the surface was anything but smooth. It was covered in polygons, veins, layered rock and other fine structures too small to see clearly from orbit. The patterns continued in almost every direction.

Individual polygons measure only around 4 to 8 centimeters, or roughly 1.5 to 3 inches, across. Together, they form an extensive honeycomb-like network over the light-toned bedrock. The textured terrain also surrounds a nearby layered butte nicknamed Miraflores, whose top has accumulated orange Martian dust and sand.

What carved the Martian honeycomb?

Scientists are considering several possible explanations.

One is that the polygons began as mud cracks. Under this scenario, water soaked fine sediment before evaporating, causing the surface to shrink and fracture. Repeated wet and dry episodes could then have modified the cracks over time.

Another possibility involves temperature. Large swings between warmer and colder conditions can repeatedly expand and contract rock or sediment until fractures develop.

The cracks may also have formed underground. As additional material accumulated above wet sediment, the increasing pressure could have squeezed out water and fractured the compacted layers.

Curiosity’s instruments are now examining both the raised ridges and the flatter material inside the polygons. The rover has used its APXS instrument to study their elemental chemistry, its MAHLI camera to obtain close-up images and its ChemCam laser to analyse selected targets. Those measurements should help researchers determine whether the entire field formed through one process or records several episodes in Gale Crater’s history.

Organic chemistry adds another piece

Curiosity has also continued to find evidence that ancient Mars possessed some of the chemical ingredients associated with habitable environments.

In April 2026, NASA announced that scientists had identified 21 carbon-containing molecules in a clay-rich rock sample collected by Curiosity. Seven had never previously been detected on Mars. One contained a nitrogen-bearing ring structure of a kind that can act as a precursor to more complex molecules related to RNA and DNA.

But compounds aren’t evidence of life. Organic molecules can arise through biological activity, but they can also form through abiotic chemical and geological processes.

The polygon field could now add environmental context to that chemistry. Establishing how the fractures formed may reveal whether this part of Gale Crater experienced isolated bursts of water, repeated wet and dry cycles, temperature-driven cracking or changes that happened after the sediment was buried.

Ultimately, this is exactly the type of observation that makes Curiosity so valuable.

Curiosity landed in Gale Crater in August 2012 and has spent nearly 14 years reading the history preserved in its layered rocks. The rover has found evidence of ancient rivers, long-lived lakes and environments that once contained the water, chemistry and energy sources potentially needed by microorganisms.

Piece by piece, those cracks may help reconstruct how Gale Crater changed from a place shaped by lakes and streams into the cold, dry landscape Curiosity explores today.