China’s Zhurong rover has found evidence of liquid water on present-day Mars, according to a team that reviewed data from the rover’s cameras.
To be clear, the team claims they’ve collected evidence of liquid water on Mars—not the liquid water itself. Water was once plentiful on Mars. NASA, the European Space Agency, and others have found a plethora of evidence for ancient water on the planet; it’s proving the recent presence of water that’s trickier.
The (currently malfunctioning) Zhurong rover is sitting on the southern edge of Utopia Planitia, a vast series of volcanic plains on Mars. The rover landed there in May 2021. The recent team of researchers used three of the rover’s instruments—two of its cameras and its surface composition detector (MarSCoDe) to analyze the makeup of the dunes in the immediate vicinity of the rover’s landing site. Their research is published today in Science Advances.
“According to the measured meteorological data by Zhurong and other Mars rovers, we inferred that these dune surface characteristics were related to the involvement of liquid saline water formed by the subsequent melting of frost/snow falling on the salt-containing dune surfaces when cooling occurs,” Qin Xiaoguang, a geophysicist at the Chinese Academy of Sciences, said in an academy release.
Mars’ atmosphere is only 1% the density of Earth’s, making it difficult for liquid water to exist on Mars today. But frozen water crops up regularly, in the form of possible subsurface lakes and even relict glaciers on the planet’s surface.
The researchers found that the dunes, which date to between 400,000 and 1.4 million years old, were rich in hydrated sulfates and possibly contain chlorides. “This is important for understanding the evolutionary history of the Martian climate, looking for a habitable environment, and providing key clues for the future search for life,” Qin said.
Based on the age of the dunes, they may have been hydrated when water vapor moved from the planet’s polar ice sheet to its equator, making the planet’s lower latitudes more humid. Like the discovery of the glacial remnants on Mars, these findings boost humankind’s hopes for water’s ability to persist near Mars’ relatively balmy equator, where potential human missions would be based.
The findings come amid some dark times for Zhurong. Earlier this week, the chief designer of China’s Mars exploration program told state media that the Zhurong team has not had any communication with the rover since it entered a hibernation mode in May 2022.
The rover went dormat to endure the chilly Martian winter, but its solar panels have not gotten enough sunlight to reboot operations. It’s possible that dust has accumulated on the solar panels, reducing the amount of sunlight the rover can convert into power. This was the phenomenon that doomed NASA’s InSight lander, which was effectively suffocated by dust; that mission officially ended in December.
Whether Zhurong emerges from its prolonged slumber remains to be seen, but at least it managed some valuable scientific observations before it closed its robotic eyes.
More: New Map of Mars Shows Where It Was Once Covered in Water