NASA's Perseverance rover on Mars has seen its future and is full of rocks. Lots and lots of stones. After spending the summer touring Jezero Crater and checking out the views, it’s time for Percy to get to work, testing the geological history of his new home and looking for signs of old microbial life.
“We were actually on a road trip,” Jennifer Trosper, project manager, based at NASA’s Jet Propulsion Laboratory in Pasadena, California, said at a July 21 press conference. "And during that, we'll take our first sample of the surface of Mars."
Percy is about 1 mile south of where he landed on February 18 (SN: 17/02/21). After heading through a region of sand dunes, accompanied by his Tagalong Ingenuity helicopter (SN: 30/04/21), the robotic explorer reached his first sampling point: a garden of flat, pale stones called paving stones. “This is the area we’re going to be delving into, both figuratively and literally, to understand the rocks we’ve been on in recent months,” said Kenneth Farley, a scientist on the Perseverance project at Caltech.
The team tried to find out if these rocks are volcanic or sedimentary. “We don’t have the answer yet,” Farley said. Images taken a few inches above the surface show what the team is facing: the rocks are full of dust and boulders, probably elsewhere, and the smoother surfaces have a mysterious purplish coating. “All of these factors conspire to prevent us from getting on the rock and seeing what it’s made of,” he said.
In the coming weeks, Percy will take a smooth cavity on one of those rocks and stay below the rough surface. The instruments of his robotic arm will then approach to produce detailed chemical and mineralogical maps that will reveal the true nature of the rocks. Then, in mid-August, the team will pull out its first sample. That sample will enter a tube that will eventually fall, along with samples from other regions, for some future mission to pick up and bring to Earth (SN: 28/07/20).
Cameras exploring further discovered future sampling sites. A small hill away shows signs of finely layered rocks that may be mud deposits. “This is exactly the type of rock we’re most interested in researching to look for potential biosignatures,” Farley said.
And the way the rocks are scattered along an ancient river delta in the distance suggests that the lake that once filled Jezero Crater has gone through multiple episodes of filling and drying. If true, Farley said, then the crater may retain "several periods of time in which we could look for evidence of ancient life that may have existed on the planet."