Persevering rover discovers ‘treasure’ of organic matter on Mars

drilling in the delta

The location of the delta makes the Jezero Crater, which spans 28 miles (45 kilometers), especially Great interest for NASA scientists. The fan-shaped geological feature, once located where a river met a lake, preserves layers of Martian history in sedimentary rocks, which formed when particles fused together in this formerly watery environment.

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

“The delta, with its diverse sedimentary rocks, contrasts beautifully with the igneous rocks—formed from the crystallization of magma—discovered in the crater floor,” Farley said.

“This juxtaposition provides us with a rich understanding of the geological history after the crater was formed and a variety of samples. For example, we found sandstone bearing grains and rock fragments that were created far from Jezero Crater.”

The expedition team named one of the rocks that Perseverance sampled as Wildcat Ridge. The rocks likely formed when mud and sand settled in a saltwater lake where it evaporated billions of years ago. The rover scraped the surface of the rock and analyzed it with a tool known as the Raman & Luminescence for Organics & Chemicals Survey, or SHERLOC.

This rock-solid stun laser acts as a fictional black light to detect chemicals, metals, and organic matter, said Sunanda Sharma, a Sherlock scientist at NASA’s Jet Propulsion Laboratory in Pasadena.

The device analysis revealed that the organic minerals are likely aromatic, or stable molecules of carbon and hydrogen, which are bound to sulfates. Sulfate minerals, often found within layers of sedimentary rocks, preserve information about the aquatic environments in which they formed.

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

“While the discovery of this class of organic matter alone does not conclusively mean that life existed, this set of observations is starting to look like some of the things we’ve seen here on Earth,” Sharma said. “Simply put, if this treasure hunt is for possible signs of life on another planet, organic matter is evidence. And we’re getting stronger and stronger evidence as we move into our delta campaign.”

Perseverance as well as the rover Curiosity has found organic matter before on the surface of Mars. But this time, the discovery occurred in an area where life may have once existed.

“In the distant past, the sand, mud, and salts that now make up the Wildcat Ridge specimen were deposited under conditions where life would have thrived,” Farley said.

“The fact that organic matter is found in such sedimentary rocks – known to preserve fossils of ancient life here on Earth – is important. However, as persistent as our instruments aboard have, other conclusions about what is in the Wildcat will have to sample. Ridge will wait until it is returned to Earth for an in-depth study as part of the agency’s Mars sample return campaign.”

Return the samples to Earth

The samples collected so far, Farley said, represent a wealth of diversity from key regions within the crater and delta, where the persistence team is interested in depositing some of the collection tubes at a specific site on Mars in about two months.

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

Future missions can collect these samples and return them to Earth for analysis using some of the most sensitive and advanced tools on the planet. Farley said it is unlikely that perseverance will find indisputable evidence of life on Mars because the burden of proving its founding on another planet is too high.

“I have studied Martian habitability and geology for most of my career and know firsthand the incredible scientific value of returning a carefully collected collection of Martian rocks back to Earth,” said Laurie Lichen, director of NASA’s Jet Propulsion Laboratory, in a statement. .

“Being weeks away from releasing amazing specimens of perseverance and only years of bringing them to Earth so that scientists can study them in great detail is truly extraordinary. We will learn a lot.”

Some of the various rocks in the delta were about 65.6 feet (20 m) apart, and each told different stories.

One piece of sandstone, called the Skinner Ridge, is evidence of rock material that was likely carried into the crater from hundreds of miles away, representing material that the rover would not be able to travel during its mission. The Wildcat Ridge, on the other hand, preserves evidence of mud and sulfur that has clumped together and formed in the rocks.

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 in this mission,” said David Schuster, a persistence-return sample scientist at the University of California, Berkeley.