Solving Mars’s geological mysteries from millions of miles away.
Two scientists in Texas A&M University’s Department of Geology and Geophysics are part of the Perseverance mission, looking for signs of ancient life on Mars.
By LESLIE LEE
NASA Mars 2020 Rover Sample Collection Animation NASA/JPL-Caltech
NASA’s Perseverance rover landed in Jezero crater on Mars on Feb. 18, 2021. For the next 687 days, the rover will search for signs of ancient microbial life.
Perseverance is exploring Jezero crater—sculpted terrain suggests it once was a deep crater lake fed by flowing rivers and may exhibit signs of ancient microbial life. Scientists also are testing technologies to help pave the way for future human exploration of Mars. Each of NASA’s Mars explorations “followed the water,” and earlier missions have shown that liquid water existed on Mars in the distant past. The rover will drill and collect core samples and then store them in sealed tubes for pickup and return to Earth by a future mission.
Two scientists in Texas A&M’s College of Geosciences are part of the Mars 2020 Perseverance rover mission: Marion Nachon and Michael Tice, associate research scientists in the Department of Geology and Geophysics.
Conducting field research on another planet
Nachon is one of only 13 scientists selected by NASA for the mission conducting research on the data from Perseverance and supporting the mission’s daily operations. Nachon’s research project will couple datasets from Perseverance’s Planetary Instrument for X-ray Lithochemistry (PIXL) and SuperCam instruments to characterize Mars’s geological record at the millimeter/micrometer scale. “Jezero crater was once filled by a lake, fed by a river,” Nachon said. “So, I’m working to characterize what happened to these sediments after they were deposited into the lake. What happened between then, billions of years ago, and now, when Mars is dry and cold? And how does this affect our search for traces of potential ancient Martian life?” Remotely from Earth, Nachon and the Perseverance team are using the data collected by Perseverance’s instruments to analyze in near real time sediment samples from the ancient river delta and lake bed in Jezero crater to look for evidence of ancient microscopic life.
Jezero Crater / MARS
“The PIXL instrument can take amazing images of rocks and show precise composition of the rocks. So it might be one of the most exciting instruments for helping the team identify and analyze potential signs of life and guide which samples will be drilled and cached and brought back to Earth by a subsequent mission,” Nachon said.
A spectrometer like no other
Tice is a co-investigator on the Mars 2020 PIXL Team, supporting the daily operations of the PIXL instrument—an X-ray fluorescence spectrometer with a high-resolution camera. PIXL can identify chemical elements at a tiny scale, and it has a camera that takes super-close-up pictures of rock and soil textures. “PIXL is basically an X-ray microscope for ‘looking’ at the elemental composition of rocks,” Tice said. “PIXL is designed to help us tell the difference between, for instance, a sandstone that formed as the result of sand rolling down the side of a ripple and a sandstone that formed as a community of microorganisms that grew on a beach.”
The scientists will use PIXL to detect and measure elements common in rocks and minerals, such as aluminum, silicon, and calcium. “PIXL works by pointing an X-ray beam thinner than a human hair at spots on the target rock, measuring the X-rays that fluoresce back at it, and then repointing at the next point to make lines, grids, or maps,” he said. “It is smart enough to be able to pick out spots on the rock that we tell it to, even when the rover arm doesn’t quite get us there exactly. It is even smart enough to be able to track those points overnight as the arm PIXL is attached to flexes unintentionally while the air temperature changes by up to 100°C (180°F). These capabilities make PIXL one of the most complex instruments to ever be placed on a NASA rover.” As Nachon, Tice, and their NASA colleagues continue their work, Perseverance will continue exploring Jezero crater, and scientists the world over will wait and watch for what, if any, signs of life they find.
MISSION OVERVIEW: NASA’s Perseverance Mars Rover
NASA's Mars 2020 Perseverance rover is searching the Red Planet for signs of ancient life, collecting samples, and helping pave the way for human exploration.