BEIJING, May 1 (Xinhua) — China’s Mars Exploration Rover “Chorong” has provided key observational evidence of liquid water in the low latitudes of Mars, the warmest regions on the Red Planet, according to a new study published in the journal “Scientific Progress” last week.
Previous studies found evidence of a large amount of liquid water in early Mars, but massive climate changes led to a severe decrease in air pressure and water vapor content, which makes it difficult for liquid water to exist sustainably on the planet at the present time, as scientists believe that Water can now only exist in solid or gaseous forms.
However, the droplets observed on the robotic arm of NASA’s Phoenix probe prove that salty liquid water can appear in summer at high latitudes on Mars. The results of the numerical simulations also indicate that suitable climatic conditions for liquid water can occur briefly in certain regions of Mars.
There was no evidence for liquid water at the planet’s lower latitudes, where surface temperatures are highest. However, the results obtained from the Churong spacecraft fill this gap.
“Churong” is part of China’s Mars Exploration Mission “Tianwen-1”. It landed on Utopia Planitia, a vast plain in the northern hemisphere of Mars, on May 15, 2021. It traveled about two kilometers and transmitted a massive amount of data to Earth before going into hibernation. Its landing site was in the low latitudes of Mars.
Since then, a team of more than 20 researchers at the Chinese Academy of Sciences has used the data obtained by the rover’s cameras and detectors to study the various scale surface features and physical compositions of the sand dunes in the landing area.
They found some important morphological features on the dune surfaces, such as scales, cracks, grains, polygonal edges, and a ribbon-like effect. The results of the data analysis showed that the surface layer of the sand dunes is rich in minerals, including hydrated sulphate, hydrated silica and freihydrate.
Chen Xiaoguang, a principal investigator working at the Institute of Geology and Geophysics under the aforementioned academy, said: “According to the meteorological data measured by ‘Churong’ and other Mars rover, we concluded that the surface properties of the sand dunes are related to the liquid salt water generated by the subsequent melting of frost and snow falling on the surface. The surfaces of sand dunes containing salt when cooling occurs.
Chen explained that the salts in the sand dunes cause frost and snow to melt at low temperatures to form salty liquid water. When the brine dries, the precipitated hydrated minerals bind the sand particles to form pebbles and crusts. Then the scales crack further by shrinkage. Repeating the process at a later time resulted in polygonal ridges and a ribbon-like effect on the surface of the shell.
In the study, the researchers estimated that the sand dunes found by Chorong were formed between 400,000 and 1.4 million years ago. The exchange of water vapor between high and low latitudes during this period led to the recurrence of moist environments at the low latitudes of Mars, and thus the recurrence of salty water when the temperatures in the region decreased.
Chen added that this discovery provides key evidence for the existence of liquid water in the low-latitude regions of Mars, where surface temperatures are relatively warm and more suitable for life than at higher latitudes.
Researchers involved in the study said that it also provides information for designing future exploration strategies for Mars rovers, as salty water was previously present at different latitudes on Mars, salt-resistant microbes should be prioritized in future missions searching for life on Mars. .
