Coastline discovered

China rover finds evidence of ancient Martian ocean

China's "Zhurong" rover (pictured) has found evidence of a former Martian ocean.

(Bild: APA/AFP/CNS/CNSA)

With the help of the Chinese rover "Zhurong", researchers have gathered new evidence that Mars was home to an ocean billions of years ago. In data that it transmitted to Earth, they found evidence of ancient coastlines on the Red Planet.

Geological data obtained by "Zhurong", which landed in the northern lowlands of Mars in 2021, would indicate an ancient coastline, report researchers from Hong Kong Polytechnic University and the China Academy of Space Technology. The rover examined rocks in Utopia Planitia, one of the largest lowlands in the planet's northern hemisphere.

Data would indicate the existence of a water ocean on Mars at a time when the Red Planet was possibly already dry and cold and had also lost much of its former atmosphere, the scientists write in the journal "Scientific Reports".

Evidence of a former coastline discovered
They described surface features such as gullies, sediment channels and mud volcano formations that indicate a former coastline - with evidence of both shallow and deeper marine environments.

This is what Mars might have looked like around four billion years ago.

(Bild: ESO/M. Kornmesser/N. Risinger (skysurvey.org))

This is what Mars might have looked like around four billion years ago.

(Bild: ESO/M. Kornmesser)

"We estimate that the flooding of Utopia Planitia took place 3.68 billion years ago. The ocean surface was probably frozen in a geologically short period of time," says planetary researcher Bo Wu from Hong Kong Polytechnic University (PolyU).

Ocean disappeared 3.42 billion years ago
The ocean then appears to have disappeared around 3.42 billion years ago, according to Wu. "The water was heavily silted and formed the layered structure of the deposits," added PolyU co-author Sergey Krasilnikov.

Like our Earth and the other planets in our solar system, Mars was formed around 4.5 billion years ago. At the time the ocean apparently existed, the Red Planet may have already begun to move away from being a hospitable planet.

"The presence of an ancient ocean on Mars has been suspected and explored for several decades, but there are still considerable uncertainties," said Wu. "These discoveries not only provide further evidence for the theory of a Martian ocean, but also provide a discussion of the likely evolutionary scenario for the first time," he says.

Rover no longer woke up from "hibernation"
The solar-powered rover "Zhurong" (named after a mythical Chinese fire god), began its work on the surface of Mars in May 2021 and was put into "hibernation" in May 2022, from which it never woke up. Probably because its solar panels are thickly covered with sand and dust after the stormy winter on the Red Planet ...