In the sky and on the ground, rovers and observers will go deep into the dunes of the red planet when they explore Mars, looking for signs of life.
Mars is finally used by NASA and the new space exploration agency. For 50 years, the search for microbial life or remnants of old life on Mars is no longer a fantasy in comics, but has entered the agenda of new space missions.
The answer that Mars rovers like Perseverance and Ex-Curiosity are looking for is a transcendent question. Not only is there life on Mars, but if there is less life on other planets than the red neighbors, they will answer. If the answer is yes, then the earth will lose its privilege as a sanctuary for universal life.
The research on the Martian dunes is related to this, and the life trajectory it pursues may one day flourish in today’s Martian wasteland. One of the targets of the research is the ancient sand dune area of Gale Crater, which is the exploration area of Curiosity Wanderers, the predecessor of Opportunity.
An international team led by Imperial College London found evidence of ancient sand dunes on Mars, which are now “submerged” in the crater.
To explain the past climate of Mars, you can examine the rocks carefully and find out what their surface looked like before depositing.
in a JGR published a new article: “Planets”, Researchers from the NASA-JPL Mars Science Laboratory mission used the Curiosity rover to demonstrate their findings by investigating the rocks in the gale crater.
They found evidence of an ancient dune field, which is today a layer of rock above the crater. The sand dunes were placed in places that were once the lake bed. The remaining rocks of the dune field are today called the Stevenson Formation.
They marched into Mount Sharp from the lake
More than 3.5 billion years ago, the lake dried up, and the sediment dug from the bottom of the lake was eroded and eroded, forming the peaks of what is now the crater (now Mount Sharp).
On both sides of the mountain, they found evidence that an ancient dune field formed behind the lake, indicating that the climate is extremely dry.
These findings help scientists understand the processes on the surface and the atmosphere—such as the direction of sand dunes being blown by wind—and potentially how the Martian climate evolves. Most importantly, they are looking for clues to find out whether the environment can retain microbial life before it becomes a habitat for microbes.
By observing the rock layers preserved in images collected by Curiosity rover, the researchers reconstructed the shape, migration direction and size of the large sand dunes (also called draas) that occupy the part of the crater.
These models show that the sand dunes are located next to the central peak of the Gale Crater-called Sharp Peak-and are eroded by the wind at an angle of 5 degrees. The study also found that they are compound: large dunes contain their own set of smaller dunes, which are oriented differently from the main dune.
Understanding the dunes
Dr. Steven Banham, the first author of the Department of Earth Sciences and Engineering at Imperial University, explained: “When the wind blows, the wind carries sand of a certain size, and then arranges them into a pile of what we think are sand dunes. Sand. These landforms are common in sandy deserts such as the Sahara, Namib dune fields and the Arabian Desert. The strength of the wind and the uniformity of its direction control the shape and size of the dunes, and their evidence can be preserved in the rock record .
“If too much sediment is transported to a certain area, the dunes can rise by migrating and partially burying adjacent dunes. These buried layers contain a feature called “cross-bed”, which can indicate the size of the dune and Their migration direction. By studying these cross-beds, we can determine that these strata are deposited by specific sand dunes that are formed when the competing winds transport sediments in two different directions.
3.5 billion years ago, two competing headwinds brought these great sand dunes into the plains of Gale Crater.
The lower part of Mount Sharp is composed of ancient sediments in the lake bed. When these craters were flooded shortly after they formed 3.8 billion years ago, these sediments piled up on the lake bed.
In the past nine years, Curiosity has spent a lot of time studying whether these rocks are signs of habitability.
However, new discoveries indicate that ancient dune fields may be less conducive to life than previously thought. Dr. Banham said: “The sand dunes are vast and not a particularly hospitable place for microbes. The records left rarely retain evidence of life, if any.”
“These desert sands represent a snapshot of time in the Gale Crater. We know that the dune field was a lake before-but we don’t know what covers the desert sandstone above Mount Sharp. It may be more layers deposited under arid conditions. , It may also be sediments related to a more humid climate. We will have to wait and see.”
The rover on Mars allows researchers to explore the Earth in more detail than ever before. Dr. Bannerm added: “Even though geologists have been reading rocks on Earth for more than 200 years, we have not been able to read Martian rocks at the same level as those on Earth until the last ten years or so.”
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