Study reveals evidence of massive floods in a Martian crater

According to a new study, a crater on Mars has experienced extensive floods around 4 billion years ago.

Whether Mars was ever occupied with water and potentially with some primitive types of life is still questioned. However, science has made huge steps to find evidence of the Red Planet's past. NASA has sent the fabled curiosity rover to explore the Gale crater and to provide researchers with new data. Curiosity rover landed on the crater in 2017 and is currently operational collecting more data.

According to scientists from NASA's Jet Propulsion Laboratory, the University of Hawaii and the Jackson State University, Cornell, some of the data retrieved by the rover showed a sedimentary sequence of the crater that suggests large floods occurred within it. “We identified megafloods for the first time using detailed sedimentological data observed by the rover Curiosity. Deposits left behind by megafloods had not been previously identified with orbiter data,” Alberto G. Fairén, co-author of the study and a visiting astrobiologist in the College of Arts and Sciences, stated. The findings were published in early November in Nature Scientific Reports.

In particular, the team found the existence of antidunes around 9 meters high distanced about 140 meters apart. Antidunes are sedimentary formations that emerge in streams and rivers when the flow of water is supercritical (the flow speed is higher than the wave velocity). Those formations are indicative of large floods.

The research team suggests that the floods may have been caused by a meteor that impacted the terrain and unleashed the ice that existed underground of the Martian surface. The heat transmitted to the ground by the impact probably sublimed the ice which was transformed into water vapor. The impact probably caused a release of carbon dioxide (CO₂) and methane (CH₄) which along with the water vapor were combined and produced a series of rainfalls that resulted in large floods.

It is probable that those rainfalls impacted the entire planet. However, the duration of this wet period cannot still be quantified yet.

It is crucial to understand that Martian geological processes do not resemble the current ones on Earth. Our planet consists of tectonic plates that shape the surface of the ground. Moreover, erosion processes from which sedimentary formations develop are mainly triggered by water and air action. Those processes have been completely halted on Mars for billions of years, hence, its geological features have frozen in time.

The new question that needs to be answered is whether any type of life (probably microbial) could have been supported on Mars in the aforementioned period. Evidence revealed that there was water on the planet some billion years ago and Mars was capable of hosting some kind of primitive organisms.