Scientists studying data from China’s Zhurong rover first discovered cracked layers on the young dunes of Mars, indicating that the Red Planet was a watery, salt-rich world 400,000 years ago.
since drop In the northern hemisphere of Mars in May 2021, the rover rolled close to four crescent-shaped orbiters Sand dunes in Utopia Planitia to investigate the composition of its surface. All four of the wind-formed miniature geological features are covered with scales, thin, cracked edges all around formed by the melting of small pockets of “new water” sometime between 1.4 million years ago to 400,000 years ago, according to new leaf (Opens in a new tab) Posted Friday (28 April).
“This implies a more recent time in the history of Mars,” Xiaoguang Qin, a scientist at the Chinese Academy of Sciences in Beijing and an author of the new study, told Space.com.
Related: Water on Mars: Exploration and Evidence
Scientists have long thought that this is early Mars It harbored abundant liquid water about three billion years ago. But dramatic weather changes have frozen much of it as the ice is now trapped in plumes and left the bulk of the planet parched.
The Zhurong Dunes explored near their landing site are in the planet’s northern hemisphere – far from the North Pole – 50 to 100 feet (15 to 30 meters) tall and about 3 feet (1 meter) wide. The latest results from analysis of images and data sent home by Zhurong and its Tianwen 1 The orbiter’s companion shows that large amounts of water from the planet’s icy polar regions moved to lower latitudes a few million years ago, settling atop the dunes of Utopia Planitia.
When Zhurong ventured near the target dune, which is pint-sized compared to the massive two-story dune from NASA’s Curiosity rover, Lesson Elsewhere on Mars, the rover’s laser-induced avalanche spectrometer (MarSCoDe) aboard has pounded sand grains into millimeter-size particles. Their chemical composition revealed hydrated minerals such as sulfates, silica, iron oxides, and chlorides. According to the study team, these minerals were formed in the presence of water at low latitudes in the late Amazonian era on Mars, which scientists previously thought was extremely dry.
Researchers say that water vapor traveled from the poles of Mars to low latitudes such as the Zurong Spot a few million years ago, when the planet’s polar ice caps released large amounts of water vapor, thanks to the different tilt that the Martian poles had. Pointing more directly at the sun. Freezing temperatures on the wobbly planet condensed drifting vapor and dropped it as snow away from the poles, according to the latest study.
Mars’ tilt changes over a 124,000-year cycle, so “this provides a replenishment mechanism for atmospheric vapor to form sleet or snow at the lower latitudes where the Zhurong rover landed,” Chen told Space.com. But “no water ice was detected by any device on the Zhurong rover.”
Instead, in the same way that salted roads on Earth melt icy patches during storms, the salts in the Martian sand dunes warmed and melted the fallen snow enough to form salt water. The researchers say the process also formed minerals such as silica and ferric oxides, which Zurong spotted.
However, the salt water did not stay for long. temperatures on Mars Violently oscillating and surging in the morning between 5 a.m. and 6 a.m., so the salt water evaporated and left behind newly formed salt and other minerals that later seeped between sand grains in the dunes, solidifying them to form a crust, according to the study.
The crust that forms on top of the dune, which is 0.5 in (1.25 cm) to 3 in (1.7 cm) deep, will likely have solidified within one year, because the dune will not remain in place long enough to solidify through millennia. It then cracked as high temperatures dried it out so much that it “should be tough and resist wind erosion,” Chen said.
“This phenomenon has been documented in one location, but it should be applicable to a relatively large portion of the Martian surface at similar latitudes,” said Manasvi Lingam, an assistant professor of astrobiology at Florida Institute of Technology who was not involved in the new experiment. . Research, tell Space.com.
Since Zhurong, which is now choked under Dust covered solar panelsIn the new study, the researchers proposed future missions to search for salt-tolerant microbes, perhaps such as brine or pickled shrimp found in the Great Salt Lake in Utah, United States.
This research is described in a paper (Opens in a new tab) Published on Friday (April 28) in the journal Science Advances.
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