Finding faint signs of water on Mars

belbalady.net There is ample evidence that Mars was once much hotter and wetter, with abundant flowing and standing water on its surface.

Over time, as the Martian atmosphere was slowly stripped away, much of this water was lost to space, and what remained was mostly concentrated around the poles as glacial ice and permafrost.

Over the years, space agencies have sent robotic landers, spacecraft, orbiters and rovers to Mars to learn more about how and when this change took place. Mars may have had liquid water much later than previously thought, according to China’s Tianwen-1 mission, which includes the Zhurong rover.

According to new research from the Chinese Academy of Sciences (CAS), the Zhurong rover discovered salt-rich dunes on Utopia Planitia that showed cracks and crusts that indicate water may have existed a few hundred thousand years ago.

The research team was led by scientists from the Principal Laboratory for Cenozoic Geology and Environment and the Principal Laboratory for Lunar and Deep Space Exploration (part of the National Astronomical Observatory) at the Institute of Geology and Geophysics.

They were joined by several additional researchers from these institutions, the School of Earth and Planetary Sciences, and the Institute of Atmospheric Physics. He described the findings in a paper published April 28 in Science Advances.

As they describe, the Surang rover observed interesting features on the surface of Parson Dunes on Utopia Planitia, a massive plain and the largest impact basin in the Solar System. These dunes are a unique feature of Mars’ northern hemisphere, similar to the sand dunes that appear in deserts across Earth.

This is caused by high winds depositing sand in a crescent shape with the curved side facing downwind. Observing a section of the sand dunes on the southern side of Utopia Planitia, Jurong noticed flakes, cracks, clumps, and shiny polygonal ridges.

The team concluded that these features formed from small pockets of water from melting ice or snow mixed with mineral salts. As water sublimated into the Martian atmosphere, it left behind a hard crust and aggregates with depressions and ridges. Like other features that formed in the presence of water, they were protected by the extremely dry and cold atmosphere of Mars.

But unlike other features that are hundreds of eons or even billions of years old, the team estimates that these features formed between 1.4 million and 400,000 years ago.

During this period, the atmosphere on Mars was similar to what it is today (i.e. very cold and dry). Therefore, these results indicate a recent hydrological cycle on Mars, which is much more recent than previously thought.

The team ran computer simulations and combined them with observations made by other robotic missions. These results suggest that other regions on Mars may be suitable for frost and ice formation at certain times of the year, leading to similar features elsewhere.

This is consistent with observations made by robotic missions since NASA’s Viking 1 and 2 missions explored Mars in the late 1970s. However, the general consensus among scientists is that morning frost occurred only in a few places and under very restricted conditions.

The discovery suggests that there may be occasional splashes of liquid water on Mars today in other areas, although the amounts are much smaller.

As the authors of the study say: “This discovery highlights the humid conditions of the modern Martian climate and provides important clues for future explorations looking for signs of survival, particularly at low latitudes with relatively warm and highly adaptive temperatures.”

The discovery may also indicate small patches of fertile surfaces where microbial life still exists today.

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