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This crater on Mars, called Jezero, was once a lake – and to the right of this image, a flood sprang up long ago by its edge, creating a canyon.
Credit: Tim Goudge / NASA
Scientists have identified 24 ancient lakes on Mars that once overflowed and crossed their walls, forming steep-walled canyons – and NASA's March 2020 rover will explore the neighborhood of one of these paleolakes, looking for traces of old life.
The Jezero crater is one of two dozen sites examined by a team of geologists for signs of canyons formation: severe flooding or slower flows over longer periods. Their results suggest that for the selected canyons, the first ones occurred, with a sudden flood rapidly digging canyons all over the Martian surface.
"These lacerated lakes are quite common and some of them are quite big, some as big as the Caspian Sea," said lead author Tim Goudge, a geoscientist at the University Geoscientist. from Texas to Austin. "So we think that this type of catastrophic flooding by overflow and rapid incision of exit canyons was probably very important at the beginning of the surface of Mars." [8 Cool Destinations That Future Mars Tourists Could Explore]
The team came to this conclusion by examining the relationship between the canyon measurements and the crater rims that once contained all this water. As the size of the canyon increased in proportion to the size of the nearby lake, the team estimated that the 24 lakes had violently crossed their walls and dug the canyons in just a few weeks. If they had not seen such a correlation, they would have rather suspected that the canyons were gradually forming from a milder water flow.
And unlike the geological features here on Earth, lake beds and canyons remain etched on the surface of the planet Mars because there is no modern plate tectonics that can mix and destroy them.
"The earth's landscape has not preserved the great lakes for a very long time," said co-author Caleb Fassett, a scientist in planetary science at NASA, in the same statement. "But on Mars … these canyons have been here for 3.7 billion years, a very long time, and that gives us an idea of what deep surface water looked like on Mars."
This long Martian surface offers scientists the hope that they could access ancient sediments that may contain the remains of life that once existed on Mars. That's partly why NASA chose to send its March 2020 rover, due to landing on the Red Planet in 2021, at Jezero Crater, where it can study five different types of rocks. and chase away all vestiges of ancient life that might be hiding. such a once humid environment.
The new research is described in an article published November 16 in the journal Geology.
Email Meghan Bartels at [email protected] or follow her. @meghanbartels. follow us @Spacedotcom and Facebook. Original article on Space.com.
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