Even though we’re learning more about Mars than ever before thanks to rovers, orbiters, and landers visiting the planet, there’s still a whole lot we have to learn about how Mars formed, its history, and what it’s made up of now. The Perseverance rover has been exploring Mars’ Jezero crater since it landed there in 2021, and now scientists have released a batch of new research which could help us get a better understanding of the planet’s history and geology.
One big finding is that rocks that Perseverance has found on the floor of the Jezero crater are igneous rocks, formed from cooling lava. That’s exciting because it helps scientists to put dates on events in Martian history, such as when the rocks interacted with water. “From a sampling perspective, this is huge,” said one of the researchers, David Shuster of the University of California, Berkeley, in a statement. “The fact that we have evidence of aqueous alteration of igneous rocks — those are the ingredients that people are very excited about, with regard to understanding environmental conditions that could potentially have supported life at some point after these rocks were formed.”
“One great value of the igneous rocks we collected is that they will tell us about when the lake was present in Jezero. We know it was there more recently than the igneous crater floor rocks formed,” explained Ken Farley of Caltech, Perseverance’s project scientist and the lead author of one of the recent papers in another statement. “This will address some major questions: When was Mars’ climate conducive to lakes and rivers on the planet’s surface, and when did it change to the very cold and dry conditions we see today?”
Igneous rocks are great for understanding the history of water on the planet, but they aren’t so good for another of Perseverance’s jobs: looking for signs of ancient life. If there ever was life on Mars, our best hope of finding evidence of it would be to look at sedimentary rocks, which often form in watery conditions when layers of sediment are carried through lakes or rivers.
To find these sedimentary rocks, Perseverance is currently exploring an area of Jezero where there was once a river delta. This delta will be rich in sedimentary rocks which Perseverance is collecting samples from so they can be brought back to Earth for study in a future Mars Sample Return mission.
