Data from China’s Zhurong rover has revealed what appears to be an ancient coastline running through the northern hemisphere of Mars.
Scientists studying data sent back by the Zhurong rover report that these findings provide new evidence for the long-standing hypothesis that an ancient ocean once covered the northern part of Mars billions of years ago.
Since Zhurong landed in 2021 at one of the largest and oldest impact basins on Mars, known as Utopia Planitia, the rover has traveled about 2 kilometers to study the surrounding geology in search of signs of water or ice.
An image captured by China’s Zhurong Mars rover during the Tianwen-1 mission. (Photo: China News Service).
Discovering Signs of Water on Mars
By combining observations from the rover’s camera and ground-penetrating radar with remote sensing data from orbiting satellites, Bo Wu at the Hong Kong Polytechnic University and colleagues have identified several water-related features around the rover’s landing site. These include cone-shaped structures resembling volcanic craters, channels, sedimentary troughs, and mud volcanoes, which the research team interprets as evidence of an ancient coastline.
Based on the composition of surface sediments in the area, this ocean may have existed around 3.68 billion years ago, according to a paper detailing the findings published in the journal Scientific Reports.
The presence of water, an essential component for life as we know it, and an ancient ocean on Mars suggests that Mars once had conditions favorable for supporting microbial life. Scientists continue to piece together how all that water began to disappear into space about 3 billion years ago. Much of the drainage is known to have been accelerated by frequent solar storms from a young sun that stripped away Mars’ thick atmosphere.
Scientists also believe that at least part of the ocean must have vanished underground. Data from NASA’s InSight lander recently found enough water to cover Mars with a deep ocean one to two kilometers in thickness, which has seeped into the planet’s crust, where it is stored in cracks and tiny pores. Despite this, InSight found no evidence of life on Mars.
