Mars was once home to raging rivers and lakes formed in craters which often burst carving out vast canyons in just weeks, a new study found.
On Earth canyons take millions of years to be gouged out from the surface.
But on the Red Planet catastrophic floods were unleashed when these lakes became so overfilled they burst their banks to carve canyons very rapidly.
And the flood waters left their mark on the surface of the Red Planet that can still be detected billions of years later.
Now most of the water on Mars is locked away in frozen ice caps.
But scientists at The University of Texas at Austin found evidence of the catastrophic geologic processes may have had a major role in shaping the landscape of Mars and other worlds without plate tectonics
Lead author postdoctoral researcher Dr Tim Goudge, at the UT Jackson School of Geosciences said: “These breached lakes are fairly common and some of them are quite large, some as large as the Caspian Sea.
“So we think this style of catastrophic overflow flooding and rapid incision of outlet canyons was probably quite important on early Mars’ surface.”
Satellite images of rock formations showed evidence hundreds of craters across the surface of Mars were once filled with water.
More than 200 of these “paleolakes” have outlet canyons tens to hundreds of kilometers long and several kilometers wide carved by water flowing from the ancient lakes.
However, until now, it was unknown whether the canyons were gradually carved over millions of years or carved rapidly by single floods.
Using high-resolution photos taken by NASA’s Mars Reconnaissance Orbiter satellite, the researchers examined the topography of the outlets and the crater rims of 24 paleolakes and their outlet canyons.
One of the paleolakes examined in the study, Jezero Crater, is a potential landing site for NASA’s Mars 2020 rover mission to look for signs of past life.
Dr Goudge and NASA scientist Dr Caleb Fassett proposed the crater as a landing site based on prior studies that found it held water for long periods in Mars’ past.
They found a correlation between the size of the outlet and the volume of water expected to be released during a large flooding event.
If the outlet had instead been gradually whittled away over time, the relationship between water volume and outlet size likely wouldn’t hold
While massive floods flowing from Martian craters might sound like a scene in a science fiction novel, a similar process occurs on Earth when lakes dammed by glaciers break through their icy barriers.
And the similarity is more than superficial.
As long as gravity is accounted for, floods create outlets with similar shapes whether on Earth or Mars.
Dr Goudge said: “This tells us that things that are different between the planets are not as important as the basic physics of the overflow process and the size of the basin.
“You can learn more about this process by comparing different planets as opposed to just thinking about what’s occurring on Earth or what’s occurring on Mars.”
But they fit into different geological paradigms as on Earth, the slow-and-steady motion of tectonic plates dramatically changes the planet’s surface over millions of years.
In contrast, the lack of plate tectonics on Mars means that cataclysmic events – like floods and asteroid impacts – quickly create changes that can amount to near permanent changes in the landscape.
Dr Fassett concluded: “The landscape on Earth doesn’t preserve large lakes for a very long time.
“But on Mars … these canyons have been there for 3.7 billion years, a very long time, and it gives us insight into what the deep time surface water was like on Mars.”
The study was published in the journal Geology.
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