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STRANGE UNDERGROUND POLYGONS ON MARS HINT AT THE PLANET’S WET PAST
The newfound honeycomb fractures are evidence that Mars was once tilted more extremely than it is today
Reported by Sharmila Kuthunur
Buried dozens of metres under the equator of Mars is a large honeycomb pattern similar to what’s found near Earth’s frigid B poles. Each crevasse spans 70 metres (230 feet) – about half a football field – and is bordered by 30-metre (98-feet) wide slurries of ice and mud. It’s likely that this material is somewhere between 2 billion and 3.5 billion years old. The patterns were spotted in the data sent home by China’s now-incommunicado Zhurong rover, which explored an expansive, bumpy region north of Mars’ equator named Utopia Planitia.
Zhurong rolled just a little over one kilometre (0.6 miles) towards Mars’ southern region in one year of operations, but even during such a short trip, its radar had sensed a continuous pattern of 15 buried polygons – suggesting there may be more waiting to be found. On Earth, similar patterns are known to form only in Greenland, Iceland and Antarctica when drastic temperature dips caused by seasonal changes contract and fracture the ground. Ice and mud that sometimes fill these cracks stop them from ever healing, causing the surface to eventually split further. A similar process on Mars in its ancient past would have caused the newly detected crevasses, which are tens of metres larger than any found on our planet. “These polygons are huge,” said study lead Lei Zhang of the Chinese Academy of Sciences.