Looking for life on Mars

Lab-designed SuperCam will use a laser and a microphone to identify signs of life on the red planet.

By J. Weston Phippen | February 16, 2021

Mars Women
From left: Suzi Montaño, Adriana Reyes-Newell, Roberta Beal, Lisa Danielson, Nina Lanza, and Cindy Little comprised ChemCam’s engineering operations team. Los Alamos National Lab

The Mars rover Perseverance was launched on July 30, 2020, from Florida’s Cape Canaveral Air Force Station and landed in the red planet’s Jezero Crater on February 18, 2021. The car‑sized rover is equipped with SuperCam, a “Swiss Army Knife” of instruments that can help detect signs of past and present life on Mars. SuperCam was designed and built at Los Alamos with help from the Institut de Recherche en Astrophysique et Planétologie in France.

“Women tend to have a different life experience working in the sciences, and they bring those experiences to solving problems."- Nina Lanza

SuperCam looks for signs of life in rocks using a laser beam. One of the laser beam’s wavelengths is in the infrared spectrum and, from 25 feet away, blasts a pencil-tip-size hole into rocks on the surface of Mars. The second beam, in the green wavelength, uses Raman and luminescence spectroscopy, which makes organic material—life—glow. Both are helpful in identifying manganese, a kind of varnish on rocks that forms in arid environments. On Earth at least, tiny microorganisms that live in the cracks of a rock’s structure, even beneath the outer rock layer, help create this manganese varnish. So on Mars, the thinking is that where there’s manganese, there may have once been life. Or, possibly, there may even still be life.

Mars2
The Mars 2020 rover will carry SuperCam, designed at Los Alamos.

Adriana Reyes-Newell is SuperCam’s laser-blasting specialist. At Los Alamos, Reyes-Newell has spent years zapping a variety of rocks in a pressure chamber that’s designed to simulate the Martian environment, so that the scientists operating the Mars lasers will have data from Earth they can compare to what’s found on Mars.

“That way,” Reyes-Newell says, “if we shoot a target on Mars that says it has a high percentage of manganese, we can validate those findings from our past experiments here at the Lab.”

Reyes-Newell, together with colleagues Nina Lanza and Ann Ollila, has also spent years working on SuperCam’s predecessor, ChemCam, which deployed on the Curiosity rover in 2012 and still roams the red planet.

This trio, alongside Carene Larmat and Erin Dauson, are working together on a Laboratory Directed Research and Development team, studying the acoustics of laser zaps at Martian pressure. “Women tend to have a different life experience working in the sciences,” Lanza says of this all-female team, “and they bring those experiences to solving problems. At Los Alamos, that helps because it’s all of our jobs to solve problems in new ways that have never been done before.”

The women are getting plenty of data from another feature on SuperCam: a microphone that, for the first time, relays to Earth sounds from the Martian planet. When the SuperCam laser zaps a rock, it creates a supersonic shockwave. By analyzing the wavelength recorded by SuperCam’s microphone, the team found that different chemicals in rocks make different snaps or pops when blasted with the laser. They hope to compile a kind of library of these sounds, represented in wavelength data for a sequence of 30 zaps, that can be used to verify the chemical makeup of what SuperCam is zapping.

This could become helpful when it’s time for Perseverance to return rock samples to Earth. There are only 43 rock sample tubes on Perseverance, and each is coveted. But because Perseverance will relay data back about once every day on Mars, if Reyes-Newell and Lanza can correctly identify the sound of manganese rock layers popping, it will help scientists across the world decide which rocks to gather based on which have the greatest chance of containing microbes.

“There’s no smoking gun to be able to say ‘this is life,’ or ‘this was life’ on Mars without returning samples to Earth,” Lanza says. But with this novel approach to listening to rock layers being vaporized, scientists will have a better chance of finding a rock that just might contain life from Mars.