Signs of life on Mars? The Perseverance rover begins the hunt

NASA’s Mars 2020 Perseverance rover has begun its search for signs of ancient life on the Red Planet. By flexing its 7-foot (2-meter) mechanical arm, the rover tests the sensitive detectors it carries, capturing their first scientific readings. In addition to analyzing rocks using x-rays and ultraviolet light, the six-wheeled scientist will zoom in on close-ups of tiny segments of rock surfaces that could show evidence of past microbial activity.

Called PIXL, or Planetary Instrument for X-ray Lithochemistry, the rover’s X-ray instrument provided surprisingly strong scientific results while still being tested, said Abigail Allwood, PIXL’s principal investigator at Jet Propulsion. NASA Laboratory in Southern California. Located at arm’s length, the lunchbox-sized instrument fired its x-rays at a small calibration target – used to test the instrument’s settings – onboard Perseverance and was able to determine the composition of Martian dust clinging to the target.

“We got our best compositional analysis of Martian dust before it even looked at the rock,” Allwood said.

This is just a small taste of what PIXL, combined with other arm instruments, should reveal as it focuses on promising geological features in the weeks and months to come.

Scientists say Jezero Crater was a crater lake billions of years ago, making it a prime landing site for Perseverance. The crater has long since dried up and the rover is now making its way across its red, broken ground.

“If life were there in Jezero Crater, proof of that life could be there,” said Allwood, a key member of Perseverance’s “arm science” team.

To obtain a detailed profile of rock textures, contours and composition, PIXL maps of chemicals in a rock can be combined with mineral maps produced by the SHERLOC instrument and its partner, WATSON. SHERLOC – short for Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals – uses an ultraviolet laser to identify some of the minerals in the rock, while WATSON takes close-up images that scientists can use to determine size, roundness and grain texture, all of which can help determine how rock formed.

WATSON’s early close-ups have already provided a wealth of data on Martian rocks, the scientists said, such as a variety of colors, grain sizes in the sediment and even the presence of “cement” between the grains. Such details can provide important clues to the formation history, water flow, and potentially habitable ancient Martian environments. And combined with those from PIXL, they can provide a broader environmental and even historical overview of Jezero Crater.

“What is the bottom of the crater made of? What were the conditions on the bottom of the crater?” asks Luther Beegle of JPL, the principal investigator of SHERLOC. “This tells us a lot about the early days of Mars, and potentially how Mars formed. If we have any idea what the history of Mars looks like, we will be able to understand the potential to find evidence. of life.”

The scientific team

While the rover has significant autonomous capabilities, such as driving through the Martian landscape, hundreds of terrestrial scientists are still involved in analyzing the results and planning further investigations.

“There are almost 500 people on the science team,” Beegle said. “The number of participants in an action given by the rover is in the order of 100. It’s great to see these scientists agree to analyze the clues, prioritize each step and put the pieces of the Jezero scientific puzzle together. “

This will be essential when the Mars 2020 Perseverance rover collects its first samples for a possible return to Earth. They will be sealed in super clean metal tubes on the Martian surface so that a future mission can retrieve them and send them back to the home planet for further analysis.

Despite decades of investigation into the question of potential life, the Red Planet has stubbornly kept its secrets.

“March 2020, in my opinion, is the best opportunity we will have in our lifetime to answer this question,” said Kenneth Williford, associate scientist for the Perseverance project.

Geological details are essential, Allwood said, to put any indication of possible life into context and to verify scientists’ ideas on how a second example of the origin of life might come to be.

Combined with the rover’s other instruments, the detectors on the arm, including SHERLOC and WATSON, could make humanity the first discovery of life beyond Earth.

Learn more about the mission

A key focus of Perseverance’s mission to Mars is astrobiology, including looking for signs of ancient microbial life. The rover will characterize the past geology and climate of the planet, pave the way for human exploration of the Red Planet, and be the first mission to collect and cache Martian rock and regolith (shattered rock and dust).

Subsequent NASA missions, in cooperation with ESA (European Space Agency), would send spacecraft to Mars to collect these sealed samples on the surface and return them to Earth for further analysis.

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

JPL, which is managed for NASA by Caltech in Pasadena, Calif., Built and manages the operations of the Perseverance rover.

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More information:
To learn more about Perseverance, please visit mars.nasa.gov/mars2020/ and nasa.gov/perseverance