Scientists believe the polygon structures were formed by freeze-thaw cycles.
A space probe sent to Mars by China discovered strange polygon structures buried underneath the Red Planet's surface. According to IFL Science, the Zhurong mission landed in Utopia Planitia, one of Mars' biggest impact basins. The area was first visited by Viking 2 in 1976, but the latest discovery is making wave among the scientific community. Though the Zhurong mission sent the data last year, results of its analysis have surfaced recently and presented new insights in to the planet's make-up.
The Zhurong mission was part of China's Tianwen-1 Mars exploration mission and landed on the Red Planet's surface in May 2021. Though it was designed 90 Martian days (93 Earth days), the mission remained active for 356.5 Earth days before going into hibernation in May 2022.
The polygon structures were discovered 35 metres (115 feet) underground using Zhurong's ground penetrating radar.
Scientists believe the structures were formed by freeze-thaw cycles that led to the formation of cracks in the terrain. A detailed about the discovery has been published in Nature.
This implies that there was a strong palaeoclimatic variability at low-to-mid latitudes, potentially due to the high obliquity of ancient Mars, the Chinese researchers wrote in the study.
Proof of the freeze-thaw activity has been seen on Mars earlier too, and those structures were named spiders. This process may have been going on for billions of years.
Earlier studies focussed on the vertical layers of the region, which indicate that there have been several episodic floods that filled the basin, roughly around three billion years ago. The new study uncovered what the layers are like horizontally by looking at the radar analysis.
The study holds importance because if the polygon structures were formed by freezing-thawing events, it suggests the climate of Mars could have been different
Mars has the tallest volcano in the Solar System, as per the IFL Science report. Some geological activity persists to this day, with Marsquakes recorded on the Red Planet by NASA's InSight.