China’s Zhurong rover has found compelling evidence of a shoreline from a short-lived ancient ocean on Mars.
This new evidence is lending credence to the theory that Mars was once a water world.
China’s Zhurong rover touched down in Mars’ Utopia Planitia in 2021, a region with a suspected watery past. The rover went inactive in May 2022 due to harsh conditions, but its data remains valuable.
The rover’s data has provided some intriguing features around this landing area.
Among these features are pitted cones, likely remnants of mud volcanoes, which often form in areas with water or ice. Polygonal troughs and etched flows, too, suggest the presence of liquid water.
The study included researchers from Hong Kong Polytechnic University, the China Academy of Space Technology, and the Russian Academy of Sciences.
Ancient ocean in northern hemisphere
Using remote sensing and in-situ data, the team identified water-related features, including sedimentary deposits and subsurface layers.
This study suggests an ancient ocean deposited rocks on Mars’ surface 3.5 billion years ago. The ocean’s surface probably froze, and over the subsequent 230 million years, it gradually receded and ultimately vanished.
Utopia Planitia, located in Mars’ northern hemisphere, is believed to have been part of an ancient ocean.
Researchers discovered that the region is divided into three zones of varying depths, including a shore area, a shallow sea area, and a deep marine area.
This finding further supports the theory of an ancient sea once covering the Martian northern lowlands.
Moreover, the discovery of sedimentary rocks and layered rock formations provides further evidence of past water processes.
“In situ observations including sedimentary deposit rocks, water-related lamination features, and subsurface sedimentary layers, also indicate past water activities,” researchers wrote in the study paper.
Short-lived ocean
As per the study, the region underwent a transition from a flooded landscape to a more arid one over billions of years.
Based on rover data and satellite imagery, the researchers estimate that Utopia Planitia flooded around 3.68 billion years ago. Following the initial flooding, the shallow and deep marine units formed.
Over a long period, the subsurface volatiles (gases and liquids) gradually dissipated, leading to the eventual drying up of the marine environment and the formation of the current geological features.
“The ocean surface was likely frozen in a geologically short period, with liquid water solidified and material deposited by sedimentary load from the water body to form the dry shallow marine unit approximately 3½ billion years ago, and later the dry deep marine unit 3.42 billion years ago,” Bo Wu, the study author, told South China Morning Post.
The team plans to study the formation of these water-related features and estimate ocean depths, comparing the shallow and deep zones to validate their model.
NASA’s Viking 2 mission landed on Mars in 1976 to explore the Utopia Planitia region. Since then, planetary scientists have speculated about an ancient ocean in the Martian northern lowlands. This study provides strong evidence and could offer insights into Mars’ early history and the impact of water on its climate and atmosphere.
The findings were published in the journal Scientific Reports.
Leave a Comment