The Zhurong rover is part of the pioneering Chinese mission that landed on Mars, exploring the Utopia Planitia, one of the Red Planet’s largest impact basins. This mission marked a significant technological advancement, and proved that decades after the Viking 2 mission in 1976, Mars still holds numerous secrets. One of the most notable discoveries is the unearthing of 16 polygonal structures below the planet’s surface.
Scientists believe these polygonal formations were created by freeze-thaw cycles, which led to the formation of cracks in the Martian terrain. Similar to other terrains on Mars, where sublimation and freezing carve the terrain in peculiar ways, the structures indicate that these processes have been ongoing for billions of years.
Zhurong’s radar analysis revealed that buried beneath 35 meters of ground, there are cracked terrains with horizontal layers. Initially, researchers focused on the vertical layers, suggesting episodic floods that filled the basin around 3 billion years ago. However, by studying the radar analysis across 1.9 kilometers, they uncovered new information about the horizontal layers.
Formation scenario for the polygonal structure buried under Utopia Planitia.
Mars was once a volcanic world with geological activity still evident today through marsquakes recorded by NASA’s InSight. However, despite considering a volcanic origin for the buried structures, there was no evidence of basaltic extrusions by Zhurong’s observations. The team is confident that the structures are sedimentary, indicating the influence of varying climates.
The study’s consequential findings suggest that if the polygonal structures are a result of freezing-and-thawing events, the climate of ancient Mars must have been notably variable. Utopia Planitia’s geographical location implies potentially wild seasonal changes, despite being situated 25 degrees north of the Martian equator.
Notably, the layers indicate a complex history, where the buried polygonal structures deviate from the surrounding materials, raising questions about the environment that initially formed them. The authors have published their study in Nature Astronomy.
[H/T: Universe Today]
