Chinese rover on Mars studies how planet went through climate change

Zhurong spacecraft finds ridged dunes with unusual features most likely caused by changes in wind direction

The Zhurong, left, and its lander side-by-side on the Martian surface. Photo: CNSA

A Chinese rover on the surface of Mars has been conducting research into how the planet underwent a shift in climate about 400,000 years ago.

Data captured by the Zhurong rover, which landed on Mars in 2021, indicates the wind direction on the southern Utopian Plain – a large, broad band of lava – had shifted 70° from north-east to north-west.

This caused erosion of crescent-shaped dunes that had formed during the last glacial period into dark, longitudinal ridges after the last Martian ice age.

The rover found these dunes, helping scientists to study geological formations to better understand climate processes on the planet.

Scientists from the National Astronomical Observatories, Institute of Geology and Geophysics and the Institute of Tibetan Plateau Research of the Chinese Academy of Sciences carried out the research.

Findings were published in the Nature science journal on July 5.

'Understanding Martian climate'

"The exploration and research on the climate evolution of Mars has been of great concern for a long time,” said Prof Li Chunlai, principal investigator of the study.

“Mars is the most similar planet to Earth in the solar system. Understanding Martian climate processes promises to uncover details of the evolution and history of Earth and other planets in our solar system.”

The ridges, also known as Transverse Aeolian Ridges, were previously discovered by spacecraft in the orbit of Mars but it was never clear what caused their formation.

It was also estimated that a change in the angle of the rotational axis of Mars caused the planet to exit its most recent ice age.

The impact caused by this change was observed on the orientation, physical properties and layering of dunes.

Climate change on Mars

Existing research had suggested the Martian climate changed over time but no geological formations had been directly measured until now.

Researchers used high-resolution orbital cameras and the rover’s terrain and multispectral camera, as well as instruments that analyse surface and meteorological properties, to capture data.

“The study was designed to integrate rover-scale data of dune formations and weather conditions to not only confirm a change in prevailing wind direction with the close of the last ice age, but also improve general circulation models used to predict finer-scale changes in seasonal wind direction,” the Chinese Academy of Sciences said.

“Importantly, prevailing wind data and dune stratigraphy at the rover landing area were consistent with the presence of ice and dust layers found at middle and higher latitudes of the planet.”

The Zhurong went into hibernation mode last May and was meant to start operations in December but has been out of action since, most likely because it is covered in dust.

It was the first Chinese rover to land on Mars. The country also placed its Tianwen-1 orbiter around Mars, which is still operational and has been sending data on the planet's atmosphere.

Tianwen-1 entered Mars's orbit on February 10, 2021, only hours after the UAE's Hope probe reached the planet.

China has plans to launch its Tianwen-2 spacecraft on an asteroid sample-return mission.