The Perseverance rover has detected potential biosignatures on Mars
After more than a year on the red planet, Perseverance has reportedly made its largest biosignature detection to date.
The rover Perseverance has taken a major step in its search for traces of ancient life on Mars with the collection of the “most valuable” samples so far, containing potential biosignatures whose nature will have to be confirmed once on Earth, announced the NASA Thursday.
If this is not yet proof that life existed on the red planet, these samples represent the best chance so far of being able to one day be able to detect with certainty a possible ancient microbial life.
A potential biosignature may have been produced by the presence of life, but also by some other mechanism not involving life. To consider this biosignature as definitive, these samples will therefore have to be analyzed by powerful laboratory instruments on Earth. NASA plans to bring them back with another mission by 2033.
I think it's safe to say it's going to be , and are already the most valuable rock samples ever collected, David Shuster of the University of California at Berkeley said at a press conference. /p>
Two cores the size of a little finger, stored in sealed tubes aboard the rover, were taken by drilling into a rock called Wildcat ridge. About a meter tall, it is located in a delta that formed about 3.5 billion years ago, where a river meets a ancient lake.
This rock is particularly interesting because it is a sedimentary rock, which seems to have formed when the water from the lake has evaporated.
Wildcat ridge thus has a high potential for retaining a biosignature, said David Shuster.
Analyzed separately by an instrument at the end of the arm robotics from Perseverance, the rock revealed the most abundant presence of organic compounds detected in a year and a half of mission.
These compounds — including carbon, which can also contain hydrogen — are the building blocks of life, said mission science lead Ken Farley.
They were detected in less quantity by the rover during previous analyzes in the crater of Jezero, which contained the lake, but as we progress in the delta, the indices become more and more strong, summarized Sunanda Sharma, a scientist at NASA's Jet Propulsion Laboratory.
I personally find these results very moving, because it seems that we are in the right place, with the right instruments, at a pivotal moment, she said.
These rocks are exactly what we came for, added Ken Farley.
Other analyzes of the rover have surprised scientists. At the bottom of the crater, they found igneous rocks, that is, rocks that crystallized after melting, Farley said.
This finding indicates active volcanism and that before receiving water, the crater may have been filled with a lava lake, he said.
Samples of these magmatic rocks have been collected, and their analysis on Earth should make it possible to directly determine the age of the surface of Mars for the first time. This is something we only indirectly infer today, explained Ken Farley.
But recovering these samples will not be an easy task.
In 2028, a mission will take off in the direction of Mars. It will carry a lander, with a mini-rocket on its back. The Perseverance rover will roll up to it, and the samples will be placed into the mini-rocket by a robotic arm.
Then, it will take off, and the precious cargo will be transferred to a vessel previously placed in orbit around Mars. Once the samples have been collected, this orbiter will return to Earth, landing in the Utah desert in 2033.
In the event of Perseverance failure, the lander will send two small helicopters to collect the samples, either going to the rover itself or to a backup reserve.
En In fact, Perseverance has been collecting two samples of each rock since the beginning of its mission. About ten of them (half of the number collected) will soon be deposited in a very flat area, where it will be easy to land if necessary. They represent the fallback samples if it became impossible to access the rover.
After leaving this treasure on the Martian surface, in the coming weeks, Perseverance will continue its exploration to fill the twenty or so still empty tubes.
The next goal will be to reach the shore overlooking the old lake, which will take about a year.