NASA’s Curiosity rover has encountered a unprecedented landscape while climbing through a Martian valley nicknamed “Valle Grande.” Images sent back by the rover show the bottom covered with honeycomb-like patterns often called polygonal fractures, each measuring about 1.5 to three inches (4 to eight centimeters) across.
Curiosity has seen small clusters of comparable geometric shapes before, but never anything approaching the size of the sector now visible in Valle Grande.
A Sea of Polygons Across Mars
The total extent of the formations appears in a 360-degree panorama captured on June 19 and 20, in the course of the 4,930th and 4,931st Martian days, or sols, of the mission. The polygons stretch across the terrain in every direction, continuing so far as the rover can see.
The patterns also climb the perimeters of a close-by butte nicknamed “Miraflores.” The formation rises 20 feet (6 meters) above the encompassing landscape and is capped by a thick layer of sand.
“We have seen a variety of fascinating landscapes through Curiosity’s eyes, but this sea of polygons took our breath away,” said the mission’s project scientist, Ashwin Vasavada of NASA’s Jet Propulsion Laboratory in Southern California. “We measured their shapes and chemistry rigorously and are hopeful there are clues in the info as to how these features formed.”
What Created the Honeycomb Patterns?
Some polygonal formations previously examined by Curiosity clearly began as cracks in drying mud. Nonetheless, several different processes can produce this type of honeycomb appearance.
Repeated warming and cooling can fracture the bottom into geometric shapes. Compression might also create similar patterns by forcing water out of sediment after the fabric becomes buried beneath the surface.
Scientists are actually studying the newly discovered formations to find out which of those processes, or possibly a mixture of them, shaped the landscape in Valle Grande.
Fourteen Years of Martian Surprises
The big polygon field is the most recent in a protracted series of unexpected discoveries made by Curiosity because it landed on Mars 14 years ago, on Aug. 5, 2012.
During its journey, the rover has encountered sulfur crystals, reflective meteorites, and lots of other unusual geologic features. More importantly, Curiosity has transformed scientists’ understanding of ancient Mars by showing that the planet once possessed water, useful chemistry, and nutrients that might have supported microbial life.
Evidence of Mars’ Watery Past
Billions of years ago, lakes and streams were scattered across the lower foothills of Mount Sharp, a 3-mile-tall (5-kilometer-tall) mountain that Curiosity has been climbing since 2014.
The rover has found chemical traces left behind by this wetter period, including carbon-based molecules believed to be precursors to RNA and DNA, two nucleic acids that carry genetic information.
Scientists cannot determine whether those organic molecules were produced through biologic or geologic processes. Each explanations remain possible. Even so, the invention confirmed once more that ancient Mars contained the chemical ingredients needed to support life.
Managed by Caltech in Pasadena, JPL built Curiosity and leads the mission on behalf of NASA’s Science Mission Directorate in Washington as a part of the agency’s Mars Exploration Program portfolio.