Looking for fossils on Mars

The researchers, who detailed their analysis in a paper published in the journal Science, also revealed that flash floods occurred in the now desolate region. "If you look at these images, you're basically staring at this epic desert landscape," Benjamin Weiss, professor of planetary sciences at MIT and a member of the analysis team explained. "There’s not a drop of water anywhere, and yet, here we have evidence of a very different past. Something very profound happened in the planet's history."

The Mars Perseverance team picked out the Jezero crater as their landing location after satellite images showed fan-shaped rock formations resembling river deltas on Earth. The new images were taken during the first three months of the rovers February arrival on Mars, a time in which it remained stationary while NASA engineers performed remote analysis of the machine's instruments. The images, captured by Perseverance's Mastcam-Z and SuperCam Remote Micro-Imager (RMI) cameras confirm that the western side of the Jezero crater was once home to a river delta.

The new MIT study explains that the lake was calm for large periods until a change in climate caused flash flooding in the region. According to the researchers, the floods carried large boulders tens of miles from higher altitudes down to the lake bed where they are still present today. Next, Perseverance will look for locations from which to collect samples that will eventually be returned to Earth by future missions. Once on Earth, these samples will be analyzed for any signs of ancient Martian life. "We now have the opportunity to look for fossils," team member Tanja Bosak, associate professor of geobiology at MIT, said. "It will take some time to get to the rocks that we really hope to sample for signs of life. So, it’s a marathon, with a lot of potential."

Pinpointing Mars' transition to a red desert wasteland

Impressively, the flood-swept boulders on the ancient Jezero crater lakebed may allow scientists to pinpoint exactly when Mars transitioned from being a habitable planet to the red desert planet we know today. "The most surprising thing that's come out of these images is the potential opportunity to catch the time when this crater transitioned from an Earth-like habitable environment, to this desolate landscape wasteland we see now," Weiss said. "These boulder beds may be records of this transition, and we haven't seen this in other places on Mars."

Since it landed on the Jezero crater on February 18, the Mars Perseverance mission has successfully ticked off a list of historic firsts, including the first controlled flight on another planet, and the first extraction of breathable oxygen from the red planet using an experimental instrument called MOXIE. The Perseverance rover will spend at least two years exploring and sampling the Jezero crater. It will leave samples in specific locations on the red planet for future Mars missions to retrieve and return to Earth. We may be incredibly close to confirming the existence of alien life in the form of long-dead microorganisms, a discovery that would vastly change our understanding and perception of the universe.