Monday, June 05, 2023

NASA, China Rovers Find Signs Of Soaked Sand Dunes, Rushing Rivers On Mars

While China's rover investigated the dune soakings, Perseverance explored the remains of a powerful torrent.
Edited by Anjali Thakur
Updated: May 28, 2023 


The findings were published in Science Advances.

NASA's Perseverance Rover and China's Zhurong rover have found signs of soaked sand dunes and rushing rivers on the red planet. China's rover found evidence that frost may have cemented dunes together as recently as 400,000 years ago. NASA's Perseverance found signs that a fast, powerful waterway once carved its way into Jezero crater, dumping water at a fantastic rate, according to a National Geographic report.

The findings were published in Science Advances. Zhurong which landed on Mars in May 2021 after it failed to wake up after a planned hibernation period, likely due to accumulation of dust on its solar panels.

NASA's Perseverance found the largest-ever river on Mars. The river was more than 66 feet deep in some places based on the height of rock formations. Scientists believe that these are preserved sandbars.

Jani Radebaugh, a researcher at Brigham Young University in Utah said that both findings "highlight the fact that it's really valuable to put things on the surface of the other planets."

China's rover discovered signs of water on the Martian surface. Sand dunes near the rover have developed a crust that likely formed as water interacted with the minerals. That water could have come from frosts that formed on the dunes in the past, or it might have fallen as snow hundreds of thousands of years ago when the planet's tilt may have allowed for snowfall in this region, reported Nat Geo.

The crusts suggest polygonal features that shrunk and expand over time. "To have these sort of shrinking and expanding features suggests there is relatively recent or modern or ongoing wetting and drying that's happening in these dune regions.

Ralph Milliken, a planetary scientist at Brown University and member of NASA's Mars Curiosity mission told Nat Geo that the dust of Mars is enriched with minerals that can absorb water vapor from the air. If that material covers the sand dunes, humidity changes through the season could cause the dust to absorb water vapour and release it again without it ever becoming liquid.

"These are likely things that are forming in lots of different places on Mars," Milliken says. "This might be a process that could be occurring over a large chunk of the planet in the recent geologic past."

While China's rover investigated the dune soakings, Perseverance explored the remains of a powerful torrent.

The NASA rover showed evidence that ancient rivers that once flowed over the planet ran much deeper, and flowed much faster than researchers previously thought. The river was part of a network of waterways that flowed in Jezero Crater. Notably, it's the area the rover has been exploring since landing more than two years ago in the hopes of eventually seeking out signs of ancient microbial life.

''Those indicate a high-energy river that's truckin' and carrying a lot of debris. The more powerful the flow of water, the more easily it's able to move larger pieces of material. It's been a delight to look at rocks on another planet and see processes that are so familiar,'' said Libby Ives, a postdoctoral researcher at NASA's Jet Propulsion Laboratory, in a NASA release.

1CommentsFor two years, Perseverance has been examining a top of an 820-foot-tall pile of sedimentary rock that stands 820 feet (250 meters) tall and features curving layers suggestive of flowing water. One location within the curvilinear unit, nicknamed ''Sprinkle Haven,'' is captured in one of the new Mastcam-Z mosaics.


China’s Rover Found Evidence of an Ancient Ocean on Mars


Elevation map of the northern hemisphere of Mars with the red star denoting the landing site of the Zhurong rover, which is ~282 kilometers (~175 miles) north of a previously proposed shoreline of the ancient Deuteronilus ocean. The different colored lines represent proposed shorelines from past studies. (Credit: ©Science China Press)

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BY LAURENCE TOGNETTI

In a recent study published in National Science Review, a team of researchers led by the China University of Geosciences discuss direct evidence of an ancient ocean and its shoreline that existed in the northern hemisphere of Mars during the Hesperian Period, or more than 3 billion years ago. This finding is based on data collected by the China National Space Agency’s (CNSA) Zhurong rover in the Vastitas Borealis Formation (VBF), which lies within southern Utopia Planitia on Mars.

The Zhurong rover landed in Utopia Planitia on May 15, 2021, after being ferried across the void from Earth to Mars by the Tianwen-1 orbiter, which is still active around the Red Planet. Zhurong was initially designed for a mission duration of 90 sols (93 Earth days) and has far exceeded that timeline. However, Zhurong entered hibernation mode in May 2022 (Sol 347) to protect itself during the harsh Martian winter. While it was scheduled to resume communications with the CNSA in December 2022, it did not, and the CNSA recently admitted it might be gone for good.

During its mission, Zhurong has traversed 1,921 meters (6,302 feet), or just under 2 kilometers (1.24 miles) and its elevation has decreased by approximately 5 meters (16.4 feet). Throughout this trek, the researchers used Zhurong’s multispectral camera (MSCam) to conduct in situ analyses of 23 rocks from 106 pairs of panoramic images, and the observations Zhurong made were striking.

a) Base map of satellite image HiRIC (HX1_GRAS_HIRIC_DIM_0.7_0004_251515N1095850E_A) (Figure 1 of the study); b) HiRISE DEM (DTEEC_069665_2055_069731_2055) overlain on the HiRIC. The red star denotes Zhurong’s landing site, with the rover traveling just under 2 kilometers (1.24 miles) between its landing site and Zhurong’s last known location (Sol_344), with an elevation decrease of approximately 5 meters (16.4 feet). (Credit: ©Science China Press)



“When we examined the photos sent back by those cameras, we found that these exposed rocks exhibited distinct layering structures, which were significantly different from the common volcanic rocks found on the Martian surface or the layering structures formed by wind-blown sand deposits,” said Dr. Xiao Long, who is a professor in the School of Earth Sciences at the China University of Geosciences, and lead author of the study. “These layering structures indicate the characteristics of bidirectional water flow, consistent with the low-energy tidal currents observed in terrestrial coastal environments on Earth.”

Essentially, the study discovered evidence of an ancient shoreline that exhibited tides on Mars based on the rover’s images, which re-examines a multitude of past studies that attempted to draw ancient Martian shorelines using orbiter data, whereas this mission was the first to conduct a direct in situ analysis on the topic.


Elevation map of the northern hemisphere of Mars with the red star denoting the landing site of the Zhurong rover, which is ~282 kilometers (~175 miles) north of a previously proposed shoreline of the ancient Deuteronilus ocean. The different colored lines represent proposed shorelines from past studies. (Credit: ©Science China Press)

On Earth, tides both advance and retreat from the shoreline from the gravitational tug with our Moon. The researchers hypothesize that since Mars has two moons, these tides could still exist in ancient ocean, although at smaller scales.



The sedimentary structures observed in the images support the hypothesis that these structures were laid down from water flow, as opposed to wind deposits. The researchers also deduce that these sedimentary structures could have been laid down during a large retreat of an ancient ocean during the Hesperian Period, as well.

Like Earth, the geologic history of Mars is split into various Epochs, also known as periods: Noachian, Hesperian, and Amazonian. The Noachian Period is estimated to have occurred between 4.1 and 3.7 billion years ago, the Hesperian Period between 3.7 and 2.9 billion years ago, and the Amazonian Period began 2.9 billion years ago and continues to the present day. While a Pre-Noachian period has been identified and discussed within the scientific community to have occurred between 4.5 and 4.1 billion years ago, no direct evidence of its existence has been found.

Artist depiction of an ancient northern ocean on Mars billions of years ago. 
(Credit: NASA/Goddard Space Flight Center)

With these incredible findings by the Zhurong rover, scientists gain new insights into the history of Mars and how much different it might have looked billions of years ago compared to the cold and dry planet it is today.

“Future exploration and sample return missions to this region will further deepen our understanding of Mars’ habitability and the preservation of traces of life,” said Dr. Long.

Numerous plans are in the works for a sample return mission from Mars by both NASA and China, as the former is collaborating with the European Space Agency (ESA) to bring Mars samples back to Earth by 2033, and China has announced a timeline that would bring samples back in 2031, beating the NASA/ESA effort by two years. NASA’s Perseverance rover recently started collecting samples and dropping sample tubes filled with Martian regolith and pebbles to be later collected by a sample return mission.

What new discoveries will scientists make about ancient Mars and its ancient shorelines in the coming years and decades? Only time will tell, and this is why we science!

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