Perseverance Rover conducts astrobiological and geological surveys on Mars – Astrobiology

NASA’s Perseverance rover has its robotic arm working around a rocky outcrop called “Skinner Ridge” in Mars’ Jezero Crater. Composed of multiple images, this mosaic shows layered sedimentary rocks off a cliff in the delta, as well as one of the spots where the rover abraded a circular patch to analyze a rock’s composition. Photo credit: NASA/JPL-Caltech/ASU/MSSS

NASA’s Perseverance Rover probes geologically rich Martian terrain

NASA’s Perseverance rover is on its second scientific campaign, collecting rock core samples of features in an area that scientists have long considered a top prospect in the search for signs of ancient microbial life on Mars. The rover has collected four samples from an ancient river delta in the red planet’s Jezero crater since July 7, bringing the total number of scientifically compelling rock samples to 12.

“We chose Jezero crater for Perseverance to explore because we thought it had the best chance of providing scientifically excellent samples – and now we know we sent the rover to the right place,” said Thomas Zurbuchen , NASA Assistant Administrator for Science in Washington. “These first two scientific campaigns have produced an amazing variety of samples to be returned to Earth from the Mars Sample Return campaign.”

Jezero Crater is 45 kilometers wide and contains a delta – an ancient fan-shaped feature that formed about 3.5 billion years ago at the confluence of a Martian river and a lake. Perseverance is currently studying the delta’s sedimentary rocks, formed when particles of different sizes were deposited in the once-watery environment. During its first scientific campaign, the rover explored the crater floor and found igneous rocks that form from magma deep underground or during volcanic activity on the surface.

“The delta, with its diverse sedimentary rocks, contrasts nicely with the igneous rocks — formed from the crystallization of magma — discovered on the crater floor,” said Ken Farley, Perseverance project scientist of Caltech in Pasadena, California. “This juxtaposition provides us with a comprehensive understanding of the geological history after the formation of the crater and a diverse sampling suite. For example, we found a sandstone bearing grains and rock fragments formed far from the Jezero crater — and a mudstone containing intriguing organic compounds.”

“Wildcat Ridge” is the name of a rock about 1 meter wide that was probably formed billions of years ago when mud and fine sand settled in an evaporating saltwater lake. On July 20, the rover abraded part of the surface of Wildcat Ridge to analyze the area using the Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals, or SHERLOC, instrument.

Analysis of SHERLOC shows that the samples exhibit a class of organic molecules that are spatially correlated with those of sulfate minerals. Sulfate minerals found in sedimentary rock strata can provide important information about the aqueous environments in which they formed.

What is organic matter?

Organic molecules are made up of a variety of compounds, mostly composed of carbon and usually containing hydrogen and oxygen atoms. They can also contain other elements such as nitrogen, phosphorus and sulphur. While there are chemical processes that produce these molecules that don’t require life, some of these compounds are the chemical building blocks of life. The presence of these specific molecules is considered a potential biosignature — a substance or structure that could be evidence of past life, but could also have been produced without the presence of life.

In 2013, NASA’s Curiosity Mars rover found evidence of organic material in rock powder samples, and Perseverance has previously detected organic material in Jezero Crater. But unlike that earlier discovery, this latest discovery was made in an area where, in the distant past, sediments and salts were deposited in a lake under conditions where life may have existed. During its analysis of Wildcat Ridge, the SHERLOC instrument registered the most common organic evidence on the mission to date.

“In the distant past, the sand, mud, and salts that make up the Wildcat Ridge sample today were deposited under conditions where life could possibly have thrived,” Farley said. “The fact that the organic matter was found in such sedimentary rock – known for preserving fossils of ancient life here on Earth – is important. However, as powerful as our instruments aboard Perseverance are, further conclusions regarding the contents of the Wildcat Ridge sample will have to await its return to Earth for in-depth study as part of the agency’s Mars Sample Return campaign.”

The first step of the NASA-ESA (European Space Agency) Mars Sample Return campaign began when Perseverance cored its first rock sample in September 2021. Along with its rock core samples, the rover has collected a total of one atmospheric sample and two witness tubes are stored in the rover’s belly.

The geological diversity of the samples already transported in the rover is so good that in about two months the rover team is considering dumping selected tubes near the base of the delta. After dropping the cache, the rover will continue its delta explorations.

“Having studied the habitability and geology of Mars for much of my career, I know firsthand the incredible scientific value of bringing a carefully collected set of Martian rocks back to Earth,” said Laurie Leshin, director of NASA’s Jet Propulsion Laboratory in Southern California . “To be weeks from delivering Perseverance’s fascinating samples and only a few years from bringing them to Earth for scientists to study in minute detail is truly phenomenal. We will learn so much.”

More about the mission

A key objective of Perseverance’s mission to Mars is astrobiology, including caching samples that may contain signs of ancient microbial life. The rover will characterize the planet’s geology and past climate, pave the way for human exploration of the Red Planet, and be the first mission to collect and cache Martian rocks and regolith.

Subsequent NASA missions, in cooperation with ESA, would send spacecraft to Mars to collect these sealed samples from the surface and return them to Earth for in-depth analysis.

The Mars 2020 Perseverance mission is part of NASA’s Moon-to-Mars exploration approach, which includes Artemis missions to the Moon that will help prepare for human exploration of the Red Planet.

JPL, managed by Caltech for NASA, built and manages the operations of the Perseverance rover.

More information on endurance: https://mars.nasa.gov/mars2020/

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