If aliens existed on Mars 3.7 billion years ago, they would have needed umbrellas
Mars was a rainy and humid place than planetary scientists thought before, according to a new study of old and inverted river channels which extend over more than 9,000 miles (14,484 kilometers) in the Noachis Noachis region of the Red Planet.
“Our work is a new element of evidence that suggests that Mars was once a much more complex and active planet than now, which is such an exciting thing to get involved,” said study manager, Adam Losekoot of the University of the United Kingdom opened in a press release.
We know that Mars was once a wet planet since the Mariner 9 Orbiter Mission of the 70s photographed a surface covered with dried river canals. These channels were dated more than 3.5 billion years ago. However, the canals cut in the ground are not the only proof of running water on Mars.
When this water took place or evaporated, it left sedimentary deposits. Sometimes we see them in craters that were formerly lakes filled with water: the NASA Rover Curiosity explores the Gale crater, which has a central peak of three miles (five kilometers high) covered with sediment.
Other times, these sediments have been placed on the beds of the river. Above the eons, the sediments would have hardened, while the river canals and the earth surrounding them would have altered and eroded. This has left the sediments, which are more resistant to erosion, going beyond major ridges. Today, geologists are calling them river winding ridges, or more clearly, inverted channels.
Now Lostkoot, which is a doctorate. The student directed the discovery of a large network of these channels in Noachis Terra based on images and data taken by the High Resolution Imaging Science Experiment (Hrise) camera and the context camera on the NASA Mars recognition orbiter, and the Marrs Orbiter Laser Altimeter (Mola) on the Defunct Mars Global Mission.
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Previously, Noachis Terra had not received attention because it did not have the most classic river channels which form more obvious evidence of water. However, by mapping the network of inverted channels, Lostkoot realized that there was a lot of evidence, there had once been abundant water in the region.
“The Mars study, in particular an under-explored region like Noachis Terra, is really exciting because it is an environment that has been largely unchanged for billions of years,” said Losekoot. “It is a temporal capsule that records fundamental geological processes in a way that is not possible here on earth.”
Some of the inverted channels appear as isolated segments that have survived elements for billions of years. Others are more intact, forming systems that travel hundreds of kilometers and are tens of meters high.
An such widespread network of inverted channels does not suggest that these channels have been caused by sudden floods, says Lostkoot. Rather, they seem to have trained in stable climatic conditions during a geologically significant period during the Noachian-Hesperian transition, which was the passage of a geological era to the next few years ago about 3.7 billion years ago.
What is particularly intriguing is the most likely source of water to have formed these inverted channels, it is precipitation – whether rain, hail or snow. Indeed, given the size of the network of inverted channels to Noachis Terra, this March region may have known many rainy days in a warm and humid climate.
It is more proof that Mars was once again like the earth than the cold and sterile desert that it is today.
Lostkoot presented its conclusions during the national meeting of the astronomy of the Royal Astronomical Society held at the University of Durham in the United Kingdom, which took place between July 7 and 11.
This article was initially published on Space.com.
