Perseverance rover finds strong clues for life on Mars in ‘treasure hunt’

Some of the recently collected samples contain organic matter, and the Jezero crater, which probably had a lake and a delta draining into it, was there. habitable environments 3.5 billion years ago.

“The rocks we studied in the delta have the highest concentration of organic matter we’ve found on the mission yet,” said Ken Farley, a Perseverance project scientist at the California Institute of Technology in Pasadena.

The mission’s mission, which began on the red planet 18 months ago, involves searching for signs of ancient microbial life. It’s durability collecting possible rock samples be he kept these stories biosignatures Today, the vehicle has 12 rock samples

Digging in the Delta

The area of ​​the delta is formed by the Jezero crater, which covers 28 miles (45 kilometers), mainly. of great interest to NASA scientists. The vent-shaped geologic feature, where a river once met a lake, preserves layers of Martian history in sedimentary rock, created when particles fused in this water-filled environment.

The rover investigated the crater floor and found evidence of igneous or volcanic rock. In its second campaign to study the delta in the past five months, Perseverance has uncovered rich layers of sedimentary rock that add further to the story of Mars’ ancient climate and environment.

“The delta, with its varied sedimentary rocks, contrasts beautifully with the igneous rocks formed from the crystallization of magma found on the crater floor,” Farley said.

“This juxtaposition provides us with a rich understanding of the geologic history after the creation of the crater and a diverse set of samples. For example, we found a sandstone carrying grains and rock fragments that originated far from the Jezero Crater.”

The mission team nicknamed one of the rocks sampled by Perseverance as Wildcat Ridge. The stone likely formed when mud and sand settled in a saltwater lake that evaporated billions of years ago. The rover skimmed the surface of the rock and analyzed it with an instrument called Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals, or SHERLOC.

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This rock-zapping laser works like a fancy black light to find chemicals, minerals and organic matter, said Sunanda Sharma, a SHERLOC scientist at NASA’s Jet Propulsion Laboratory in Pasadena.

Analysis of the instrument revealed that the organic minerals are likely aromatics, or stable carbon and hydrogen molecules bound to sulfates. Sulfate minerals, often found embedded in sedimentary rock layers, store information about the aqueous environments in which they formed.

Organic molecules are interesting on Mars because they represent the building blocks of life, such as carbon, hydrogen, and oxygen, as well as nitrogen, phosphorus, and sulfur. Not all organic molecules require life to form, as some can be created through chemical processes.

This mosaic taken by the rover shows where Perseverance sampled and abraded the rock that NASA scientists call Wildcat Ridge.

“While the detection of this class of organics alone doesn’t mean that life was definitely there, this set of observations does resemble some of the things we’ve seen on Earth,” Sharma said. “Simply put, if the search for signs of life on another planet is a treasure hunt, organic matter is a clue. And we have stronger and stronger clues as we go along in our delta campaign.”

Perseverance and even the Curiosity rovers have found organic matter on Mars before. But this time, the detection happened in an area where life could once exist.

Wildcat Ridge bedrock is a mudstone that includes organic material.  It probably formed in salt water when the ancient lake water evaporated.

“In the distant past, the sand, mud and salt that make up the Wildcat Ridge sample today were deposited under conditions where life could have thrived,” Farley said.

“Finding organic matter in such a sedimentary rock — known for harboring fossils of ancient life here on Earth — is significant. However, as sophisticated as our instruments aboard Perseverance are, more conclusions about what’s in the Wild will have to wait until the Ridge sample returns to Earth. for in-depth analysis as part of the agency’s Mars Sample Return campaign.”

Returning samples to Earth

The samples collected so far indicate the richness of diversity in key areas of the crater and delta, which has the Perseverance team interested in leaving some collection tubes at designated sites on Mars within two months, Farley said.

Once the rover drops its samples into this cache, it will continue to explore the delta.

The rover has been surveying a potential site to store its samples.

Future missions could collect these samples and return them to Earth for analysis using some of the most sensitive and advanced instruments on the planet. Perseverance is unlikely to find indisputable evidence of life on Mars because the burden of proof for establishing it on another planet is so high, Farley said.

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“I have studied the habitability and geology of Mars for much of my career and know firsthand the tremendous scientific value of returning a carefully collected set of Martian rocks to Earth,” Laurie Leshin, director of NASA’s Jet Propulsion Laboratory, said in a statement. .

“With Perseverance’s fascinating samples weeks away from deployment and just a few years away from bringing them back to Earth, it’s really exciting for scientists to study them in exquisite detail. We’ll learn a lot.”

Some of the various rocks in the delta were about 65.6 feet (20 meters), and each one tells a different story.

The larger rock and mineral fragments in the Skinner Ridge sample suggest that they came from materials transported from hundreds of kilometers outside Jezero Crater.

A patch of sandstone, called Skinner Ridge, is evidence of rocky material that was likely transported hundreds of kilometers into the crater, representing material that the rover will not be able to travel through during its mission. Wildcat Ridge, on the other hand, preserves evidence of clays and sulfates that were layered together and formed into rock.

Once the samples are in laboratories on Earth, they can reveal insights into potentially habitable Martian environments, such as chemistry, temperature and when the material was deposited in the lake.

“I think it’s safe to say that these are two of the most important samples we’ll collect on this mission,” said David Shuster, Perseverance’s sample scientist at the University of California, Berkeley.