NASA Perseverance Makes New Discoveries in Mars’ Jezero Crater

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Scientists have offered various theories as to why olivine is so abundant over such a large surface area, including meteorite impacts, volcanic eruptions, and sedimentary processes. Another theory is that olivine formed deep underground from the slow cooling of magma – molten rock – before being exposed over time by erosion.

Yang Liu of NASA’s Jet Propulsion Laboratory in Southern California and his co-authors determined that the latter explanation is the most likely. Perseverance abraded a rock to reveal its composition; Studying the exposed plot, the scientists focused on the large grain size of the olivine, as well as the chemistry and texture of the rock.

Use of the Perseverance planetary instrument for X-ray lithochemistry, or PIXLthey determined that the olivine grains in the area are 1 to 3 millimeters in size – much larger than you would expect for olivine that formed in the rapidly cooling lava at the surface of the planet.

“This large crystal size and uniform composition in a specific rock texture requires a very slowly cooling environment,” Liu said. “So most likely this magma at Jezero did not erupt to the surface.”

Unique scientific tools

The two Science Advances articles detail discoveries of scientific instruments that helped establish that igneous rocks line the floor of the crater. Instruments include Perseverance’s SuperCam laser and a ground penetrating radar called RIMFAX (Radar Imager for Mars’ Subsurface Experiment).

SuperCam is equipped with a rock vapor laser that can zap a target as small as a pencil tip up to 20 feet (7 meters) away. He studies the resulting vapor using a visible light spectrometer to determine the chemical composition of a rock. SuperCam removed 1,450 points during the first 10 months of Perseverance on Mars, helping scientists reach their conclusion about the igneous rocks at the bottom of the crater.

Additionally, SuperCam used near-infrared light – the first instrument on Mars with this capability – to find that water was altering minerals in rocks on the crater floor. However, the alterations were not ubiquitous throughout the crater floor, according to the combination of laser and infrared observations.

“The SuperCam data suggests that these rock layers were isolated from the water of Lake Jezero or that the lake existed for a limited time,” said Roger Wiens, SuperCam principal investigator at Purdue University and the Lab. Los Alamos National.

RIMFAX marks another first: Mars orbiters carry ground-penetrating radars, but no spacecraft on the surface of Mars have them before Perseverance. Being on the surface, RIMFAX can provide unparalleled detail and has probed the crater floor down to 50 feet (15 meters).

Its high-resolution “radargrams” show unexpectedly tilted rock layers up to 15 degrees underground. Understanding how these rock layers are ordered can help scientists establish a timeline for Jezero Crater’s formation.

“As the first instrument of its kind to operate on the surface of Mars, RIMFAX demonstrated the potential value of ground-penetrating radar as a tool for subterranean exploration,” said researcher Svein-Erik Hamran. principal of RIMFAX at the University of Oslo in Norway. .

The science team is excited about what they’ve discovered so far, but they’re even more excited about the science ahead.

Learn more about the mission

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

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

The Mars 2020 Perseverance mission is part of NASA’s Moon to Mars exploration approach, which includes Artemis Moon missions 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 operations of the Perseverance rover.

To learn more about perseverance:

mars.nasa.gov/mars2020/

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