China’s Mars rover Zhurong has found evidence of a coastline from a short-lived ancient ocean, adding to decades of research into the red planet’s watery past.
Data collected during the Tianwen-1 mission shows that an ancient sea might have left rock deposits on the planet’s surface 3½ billion years ago, according to a new study by researchers from Hong Kong Polytechnic University, the China Academy of Space Technology and the Russian Academy of Sciences.
In 2021, the rover started exploring the southern part of Utopia Planitia, a large plain in the northern hemisphere of Mars hypothesised to have been part of an ancient ocean that once covered the planet’s northern lowlands.
The scientists found that southern Utopia Planitia is divided into three parts with different depths, including a shallow marine section and a deep marine section, supporting the theory that the area was once covered by a sea.
The discovery of sedimentary rocks and layering in rocks and sediment are also a sign of “past water activities”, they said in an article published in the peer-reviewed journal Scientific Reports on Friday.
Lead author Wu Bo, a professor in spatial science and director of the planetary remote sensing laboratory at PolyU, said the team was the first to present a probable scenario explaining how the ocean was formed.
Based on analysis of orbital remote sensing data and observations from the Zhurong rover, the team estimated that flooding of Utopia Planitia took place around 3.68 billion years ago, according to Wu.