Per Anon., There May Have Been A Vast Body Of Water At Utopia Planitia, Relatively Recently -- Last 200 Million Years, On Barsoom: China's Zhurong Reports.

We simply. . . love this stuff. And a hat tip to Anon., for it. This one asks. . . when was Mars last. . . wet?

We are learning from the Chinese space agency's Tianwen-1 mission that Utopia Planitia contained liquid water at a time later than NASA had estimated, based on readings from our Viking lander mission, in 1970s, at the same flat Martian plain. [See legacy image, below left.]

But in the passing of nearly a half century, the instrumentation employed by Zhurong is exponentially better than NASA had available (that might survive the rough ride) on Mars then. So it is of little surprise that China has refined the world's understanding of when water last flowed on the surface of Mars. Excellent! Here's the bit, from Space.com reporting:

. . .The new study is based on data from China's Zhurong rover, which is part of the Tianwen-1 mission and touched down on the surface of Mars in May 2021. In particular, the scientists used data the rover gathered during its first 92 Martian days, or sols, at its landing site in Utopia Planitia.

Yang Liu, a researcher at the National Space Science Center (NSSC) under the Chinese Academy of Sciences (CAS), and colleagues analyzed data from three different instruments on Zhurong: the laser-induced breakdown spectrometer (MarSCoDe), the telescopic microimaging camera and the short-wave infrared spectrometer. . . .

As I say, that red coal. . . rising (with a moan) in tonight's warm Spring sky. . . will forever fire my. . . imagination. Were they. . . us? Are we, now, what they. . . became? Who knows. But it draws my eyes skyward, on clear nights, to be sure. . . smile.

नमस्ते