This story is a part Welcome to Marsour series on the study of the Red Planet.
In just a year and a half on Mars, NASA’s Perseverance rover absolutely rocked its mission. The agency held a briefing Thursday to discuss the highlights of the science mission so far, and it was a celebration of rock samples and the discovery of organics.
Organic molecules at Wildcat Ridge
A rock called Wildcat Ridge, located in the ancient river delta region of Jezero Crater, was one of the stars of the show. Percy successfully collected two mudstone samples. Wildcat Ridge is particularly fascinating because the organic molecules (called aromatics) found there are considered a potential biosignature, which NASA describes as a substance or structure that could be evidence of past life, but could also be produced without the presence of life.
The rover team emphasized that the discovery of organic matter does not mean that evidence of ancient life has been found. Organic molecules have been seen on Mars before Curiosity rover in Gale Crater as well as Perseverance which found carbon-containing molecules earlier in the mission.
Perseverance collected two core samples from Wildcat Ridge and also cleaned a round section to test the rock with a Sherloc tool.
NASA, JPL-Caltech, ASU, MSSS
The rover’s Sherloc instrument probed the rock. (Sherloc stands for Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals.) “In its analysis of Wildcat Ridge, the Sherloc instrument recorded the richest detections of organics during the mission to date,” NASA said.
Scientists see familiar signs in the analysis of Wildcat Ridge. “In the distant past, the sand, mud and salts that now make up the Wildcat Ridge pattern were deposited under conditions where life could potentially flourish,” Perseverance project scientist Ken Farley said in a statement. “The fact that organic matter was found in such a sedimentary rock known to preserve fossils of ancient life here on Earth is significant.”
Perseverance is unable to find definitive evidence of ancient microbial life on the red planet. “In reality, the burden of proof for life on another planet is very, very high,” Farley said during a press conference. To do this, we need to personally examine the rocks of Mars in terrestrial laboratories.
Fall pattern
Percy now has 12 rock samples on board, including pieces of the Wildcat Ridge and samples of another sedimentary deltaic rock called the Skinner Ridge. Earlier in the mission, he also collected samples of igneous rocks that indicate the impact of ancient volcanic activity in the crater.
NASA is so pleased with the variety of samples collected that it plans to soon release some of the filled tubes to the surface in preparation for the future Mars sample return (MSR) Company. MSR is an ambitious plan to send a lander to Mars, retrieve Percy’s samples, launch them from the surface, and return them to Earth for close study. The mission is under development. If all goes according to plan, these stones could be here by 2033.
The complexity and importance of the MSR means that NASA and its partners are developing ways to ensure that samples can be collected. It is hoped that Perseverance will be in good working order by the time the MSR lander arrives and will be able to meet it and personally deliver the samples. Leaving some samples on the ground this early in the mission in a cache in the crater will give the MSR another opportunity to get the gems on board.
Percy collected paired samples. For example, he can keep one Wildcat Ridge pipe on board and drop the other on the ground. “That we are weeks away from deploying Perseverance’s fascinating samples and just a few years away from delivering them to Earth so scientists can study them in exquisite detail is truly phenomenal,” said NASA JPL Director Laurie Leshin. “We’re learning so much.”
What’s next for Percy
As exciting as the delta is, the rover crew is looking forward to future adventures beyond it. Perseverance could wander up the rim of the crater, and the team considered several possible routes for ascent. His companion A helicopter of ingenuity in good health and expected to take to the air again.
NASA chose Jezero Crater for study because of its fascinating history of water and how rocks can preserve evidence of ancient life when it existed during more habitable times on Mars. Sherloc scientist Sunanda Sharma likened the mission to a treasure hunt for organic life on another planet, saying samples with aromatics were a clue. The Martian mystery is just beginning to unfold.