Mars is perceived as a red planet, with all its images seen by the world so far showing red rocks and craters. When NASA’s Perseverance rover landed in the Jezero Crater on Mars, scientists too hadn’t expected anything different to see. But what the rover found on the ground was surprising.
The Jezero Crater was chosen as the spot for the rover to land because of its history as a lake and part of a “rich river system, back when Mars had liquid water, air and a magnetic field”.
Analysing data from the rover, planetary scientists Roger Wiens and Briony Horgan, professor and associate professor, respectively, of earth, atmospheric, and planetary sciences at Purdue’s College of Science, made some startling discoveries, which were recently published in journals Science and Science Advances.
While the rover was expected to see sedimentary rocks “washed in by rivers and accumulated on the lake bottom”, it found many of these rocks volcanic in nature, according to a statement issued by Purdue University, which added that these rocks were found to be composed of “large grains of olivine, the muddier less-gemlike version of peridot that tints so many of Hawaii’s beaches dark green”.
I came to the ancient lakebed of Jezero Crater expecting lots of sedimentary rocks. I see them now at the old river delta, but the crater floor was a surprise: lots of volcanic rocks. 🪨Now my science team’s sharing some of what they’ve pieced together: https://t.co/HO0zRMue4h pic.twitter.com/z8ZOwqRPGG
— NASA’s Perseverance Mars Rover (@NASAPersevere) August 25, 2022
“We started to realize that these layered igneous rocks we were seeing look different from the igneous rocks we have these days on Earth. They’re very like igneous rocks on Earth early in its existence,” Wiens was quoted as saying.
It was Wiens who led the design and construction of the SuperCam on Perseverance that helps analyse samples and determine the type and origin of the rocks. Horgan, meanwhile, helped select Jezero Crater as the landing site for the rover.
According to the scientists, the rocks and lava being examined by the rover on Mars are nearly 4 billion years old. It’s not that such old rocks have not been found on Earth, but they are incredibly weather-beaten due to our planet’s active tectonic plates besides the weathering effects of wind, water and life over billions of years. On Mars, however, these rocks are pristine and hence much easier to study, the university said.