From Pittsburgh to Mars

PITTSBURGH—In 1979, Sanford Asher interviewed to join the University of Pittsburgh’s chemistry department faculty. As is the practice, he gave his interlocutors a presentation regarding a particular bit of vital research he’d do if hired.

He was hired. And in 2020, the fruit of that presentation will be on its way to Mars.

Since joining Pitt, Asher, now a Distinguished Professor of Chemistry in Pitt’s Kenneth P. Dietrich School of Arts and Sciences, has seen his job-application idea, UV Raman spectroscopy—the use of ultraviolet light as a means to excite molecules in order to determine the basic components of a piece of matter—grow and become integral to science.

This summer, he received word that the technology he created is indeed out of this world as it will be a prime component of SHERLOC, an instrument that will be aboard NASA’s Mars 2020 Rover when it lifts off in six years.

“I’ve been working in this area for a long time,” he says. “Most of the uses to this point have been biological; it’s important to the detection of protein folding. I’ve been involved in all aspects of the science from laser development to theory development to building the first instrument.”

Asher is a co-investigator on the SHERLOC instrument being built at NASA’s Jet Propulsion Laboratory (JPL), which is also leading the Mars 2020 Rover project. Luther Beegle, research scientist and deputy manager of the planetary science section at JPL, is the principal investigator on the SHERLOC (Scanning Habitable Environments with Raman & Luminescence for Organics and Chemicals) project.

“Quite frankly, SHERLOC owes a very large amount of its selection [to be aboard the rover] to Dr. Asher’s work,” Beegle says. “He’s the world’s leading expert in the field and many of the technical and scientific questions we are going to address during the Mars 2020 operations come directly from his work.”

SHERLOC, Beegle says, will shine a tiny dot of ultraviolet laser light at a target. This causes two different spectral phenomena to occur, which the instrument captures for analysis. The first is a distinctive fluorescence, or glow, from molecules that contain rings of carbon atoms. Such molecules may be clues to whether evidence of past life has been preserved. The second is an effect called Raman scattering, which can identify certain minerals, including ones formed from evaporation of salty water, and organic compounds. This dual use enables powerful analysis of many different compounds on the identical spot.

Beegle adds that Asher will play a valuable role in fine-tuning SHERLOC. “And when we land, Dr. Asher will work with the entire 2020 science team to identify the types of minerals and organics we have detected so that we can better understand Martian history.”

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