China’s Mars rover discovers signs of recent water

CAPE CANAVERAL, Fla. — Water may be more widespread and recent on Mars than previously thought, based on observations of Martian sand dunes by China’s rover.

Friday’s news comes days after mission leaders acknowledged the Zhurong rover has yet to wake up since going into hibernation for the Martian winter nearly a year ago.

Its solar panels are likely covered with dust, choking off its power source and possibly preventing the rover from operating again, said Zhang Rongqiao, the mission’s chief designer.

Before Zhurong fell silent, it observed salt-rich dunes with cracks and crusts, which researchers said likely were mixed with melting morning frost or snow as recently as a few hundred thousand years ago.

Their estimated date range for when the cracks and other dune features formed in Mars’ Utopia Planitia, a vast plain in the northern hemisphere: sometime after 1.4 million to 400,000 years ago or even younger.

Conditions during that period were similar to now on Mars, with rivers and lakes dried up and no longer flowing as they did billions of years earlier.

Although the rover did not directly detect water in the form of frost or ice, studying the structure and chemical makeup of these dunes can provide insights into “the possibility of water activity” during this period, the Beijing-based team wrote in a study published in Science Advances.

Co-author Xiaoguang Qin of the Institute of Geology and Geophysics said computer simulations and observations by other spacecraft at Mars indicate that even nowadays at certain times of year, conditions could be suitable for water to appear.

What’s notable about the study is how young the dunes are, said planetary scientist Frederic Schmidt at the University of Paris-Saclay, who was not part of the study.

“This is clearly a new piece of science for this region,” he said in an email.