NASA’s Perseverance rover is focusing its science instruments on rocks that lay on the floor of Jezero Crater, which is located on the western edge of Isidis Planitia, a giant impact basin just north of the Martian equator.
“Perseverance will help us create a timeline of when an ancient lake formed there, when it dried, and when sediment began piling up in the delta that formed in the crater long ago,” said Perseverance project scientist Dr. Ken Farley, a researcher at Caltech, and colleagues.
“Understanding this timeline should help date rock samples — to be collected later in the mission — that might preserve a record of ancient microbes.”
The WATSON camera on the end of the Perseverance’s robotic arm is taking detailed shots of the rocks.
A pair of zoomable cameras that make up the Mastcam-Z imager on the rover’s ‘head’ is also surveying the terrain.
And a laser instrument called SuperCam is zapping some of the rocks to detect their chemistry.
“These instruments and others allow us to learn more about Jezero Crater and to home in on areas they might like to study in greater depth,” the researchers said.
“One important question we want to answer: whether these rocks are sedimentary (like sandstone) or igneous (formed by volcanic activity).”
“Each type of rock tells a different kind of story,” they added.
“Some sedimentary rocks — formed in the presence of water from rock and mineral fragments like sand, silt, and clay — are better suited to preserving biosignatures.”
“Igneous rocks, on the other hand, are more precise geological clocks that allow us to create an accurate timeline of how an area formed.”
One complicating factor is that the rocks around Perseverance have been eroded by wind over time and covered with younger sand and dust.
“When you look inside a rock, that’s where you see the story,” Dr. Farley said.
While Perseverance doesn’t have a rock hammer, it does have other ways to peer past millennia’s worth of dust.
When the team members find a particularly enticing spot, they can reach out with the rover’s arm and use an abrader to grind and flatten a rock’s surface, revealing its internal structure and composition.
Once they’ve done that, they gather more detailed chemical and mineralogical information using arm instruments called PIXL and SHERLOC.
“The more rocks we look at, the more we know,” Dr. Farley noted.
“And the more we know, the better samples we can ultimately collect with the drill on the rover’s arm.”
“The best ones will be stored in special tubes and deposited in collections on the planet’s surface for eventual return to Earth.”
This article is based on text provided by the National Aeronautics and Space Administration.