Mars may be known as a desolate, dusty wasteland – but that wasn’t always the case.

Billions of years ago, the planet flowed with water and was subjected to ‘catastrophic floods’ that carved out the canyons in the landscape that are still there today.

The flooding came from gigantic lakes that would overflow with water. Now, these lakes are nothing more than huge craters pockmarking the Martian surface.

‘These breached lakes are fairly common and some of them are quite large, some as large as the Caspian Sea,’ explained Tim Goudge, a postdoctoral researcher at the University of Texas Jackson School of Geosciences.


The Hubble telescope took this snapshot of Mars 11 hours before the planet made its closest approach to Earth on August 26, 2003. (Image: Reuters)

‘So we think this style of catastrophic overflow flooding and rapid incision of outlet canyons was probably quite important on early Mars’ surface.’



Goudge, along with NASA scientist Caleb Fassett and Jackson School Professor and Associate Dean of Research David Mohrig, co-authored a paper on the flooding that was published in the journal Geology after analysing pictures of Mars from Nasa.

Until this study, it was unknown whether the canyons on Mars 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 and found a correlation between the size of the outlet and the volume of water expected to be released during a large flooding event.

Jezero crater is a paleolake and potential landing site for NASA’s Mars 2020 rover mission to look for past life. (Image: Nasa/Tim Goudge)

If the outlet had instead been gradually whittled away over time, the relationship between water volume and outlet size likely wouldn’t hold, Goudge said.

In total, the researchers examined 24 of these ‘paleolakes’ and their outlet canyons across the Red Planet.

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. Goudge and Fassett proposed the crater as a landing site based on prior studies that found it held water for long periods in Mars’ past.

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.

The Palouse River Canyon is part of the Channeled Scablands, a geologic feature in eastern Washington carved by catastrophic flooding during the last ice age. Researchers found large floods on Mars and Earth carve the land in a similar manner. (Image: Keith Ewing)

The researchers found that the similarity is more than superficial. As long as gravity is accounted for, floods create outlets with similar shapes whether on Earth or Mars.

‘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,’ Goudge said.

‘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.’

Nasa’s Caleb Fassett said: ‘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.’