China’s Mars rover Zhurong finds evidence of ancient ocean on red planet

Data from Tianwen-1 mission offers clues about coastline of short-lived sea on Martian surface around 3.5 billion years ago, researchers say

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China’s Zhurong rover is part of the country’s Tianwen-1 mission to Mars. Photo: EPA-EFE

Published: 12:01am, 8 Nov 2024Updated: 12:32am, 8 Nov 2024

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.

Surface features known as pitted cones, polygonal troughs and etched flows could be evidence of an ancient ocean on Mars, according to the researchers. Photo: Scientific Reports