At first glance, the surface of Mars looks pretty desolate. The soil is many times as dry as the driest deserts on the planet, temperatures fluctuate from one extreme to the other, and the air is extremely thin and toxic.
However, there is ample evidence that the planet was once much warmer and wetter, with much flowing and stagnant water on its surface. Over time, as Mars’ atmosphere was slowly stripped away, much of this water was lost to space, and what remains is largely concentrated around the poles as glacial ice and permafrost.
For years, space agencies have been sending robotic landers, rovers, orbiters, and rovers to Mars to learn more about how long and how long this transition took. According to China’s Tianwen-1 mission, which includes the Zhurong rover, there may be liquid water on Mars much later than previously thought.
According to new research from Chinese Academy of Sciences (CAS), the Zhurong rover observed rich salt dunes in Utopia Planitia that showed cracks and crusts, indicating that water may have been present as recently as a few hundred thousand years ago.
The research team was co-led by Xiaoguang Qin and Xu Wang Principal Laboratory of Cenozoic Geology and Ecology at the Institute of Geology and Geophysics; And Shen Ren and Jianjun Liu The main laboratory for lunar and deep space exploration (Part of the National Astronomical Observatories).
They were joined by many additional researchers from these respective institutions, and College of Earth and Planetary Sciencesand the Institute of Atmospheric Physics. Their findings are described in a paper appearing in Science advances On April 28th.
As they describe, the Zhurong rover has observed interesting features on the surfaces of the Barchan dunes in Utopia Planitia, a massive plain and the largest impact basin in the solar system. These dunes are a distinctive feature of the northern hemisphere of Mars similar to the sand dunes that appear in deserts all over the Earth.
This results from high winds depositing sand in a crescent shape, with the curved side facing downwind. Observing a patch of sand dunes in the southern part of Utopia Planitia, Zhurong noticed the crusts, 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. Once the water sublimated into the Martian atmosphere, patches of hard crust and loose material were left behind, along with depressions and ridges. Like other features formed in the presence of water, they were then preserved by the extremely cold and dry atmosphere of Mars.
But unlike other features dating back hundreds of eons or billions of years, the team estimates that these features formed between 1.4 million and 400,000 years ago (possibly recently).
As they explain in their paper, the team was able to rule out the possibility that frozen carbon dioxide (“dry ice”) and winds were responsible:
“Instead, the use of salt water from frost/melt snow is the most likely cause. This discovery sheds light on more humid conditions of the modern Martian climate and provides important clues for future exploration missions looking for signs of surviving life, especially at lower latitudes with Relatively warmer surface temperatures and more adaptability.”
During the said period, the environment of Mars was the same as it is today (i.e. very cold and dry). Therefore, these results indicate that there has been a recent hydrological cycle on Mars, which is much more recent than previously thought.
The team also ran computer simulations and combined them with observations made by other robotic missions. These results indicated that conditions may be suitable in other regions on Mars for the formation of frost and ice during certain times of the year, leading to similar features elsewhere.
This is consistent with observations made by robotic missions since NASA Viking 1 And 2 Mars exploration missions in the late 1970s. However, scientists were of the general opinion that morning frosts only occur in certain locations and under very restricted conditions.
This discovery indicates that there may be periodic splashes of liquid water on Mars today in other regions, although the amount would be very small. As the study authors say:
“This discovery highlights the wetter conditions of the recent Martian climate and provides important clues for future exploration missions looking for signs of surviving life, particularly at lower latitudes with relatively warmer and more adaptable surface temperatures.”
This discovery could also indicate that there are small patches of fertile ground where microbial life still exists today. Of course, additional studies are needed before any of this can be said with confidence. These studies may have to wait on future missions, as the rover has not yet awakened from hibernation.
According to Zhang Rongqiao, chief designer of Tianwen-1, this is likely due to dust accumulating on the rover’s solar panels. Like NASA’s Insight and Opportunity missions, this could prevent the mission from ever working again.
Since its liftoff from the Tianwen-1 lander on May 22, 2021, the rover has spent nearly a year exploring the Martian surface before going into hibernation on May 20, 2022. Since it is designed to operate for only 90 Martian (Martian) days, or 93 Day on Earth, the rover has largely outlived its lifespan.
From May 5, 2022Zhurong also managed to travel 1,921 meters (1,194 miles) across the surface. If the China National Space Agency is unable to reactivate the probe before long and decides to end the mission, Zhurong could not have chosen a deeper discovery to launch!
This article was originally published by the universe today. Read the The original article.
