by Clarence Oxford
Los Angeles CA (SPX) Aug 15, 2025
In 2024, NASA's Mars rover Perseverance retrieved an unusual specimen named Sapphire Canyon, a red mudstone with white, black-edged spots that could reveal potential sources of organic molecules on the planet.
To prepare for its eventual return, scientists from NASA's Jet Propulsion Laboratory and Caltech tested optical photothermal infrared spectroscopy (O-PTIR) on an Earth rock with similar visual traits. The method, described in Review of Scientific Instruments by AIP Publishing, uses one laser to heat a sample and another to measure surface vibrations, producing a precise chemical fingerprint.
The terrestrial test rock - a basalt with dark inclusions - was found by co-author Nicholas Heinz during a hike in Sedona, Arizona. "I was hiking in Arizona, in Sedona, when I saw this rock that just didn't look like it belonged," he said. "I put it in my backpack and brought it back to look at."
Researchers confirmed O-PTIR could easily distinguish between the basalt's base material and its inclusions, thanks to the method's high spatial resolution. Each reading took only minutes, enabling scientists to rapidly flag promising areas for deeper analysis with more sensitive tools, particularly in the search for organics.
"I hope this capability will be considered for any future material returned from Mars, an asteroid, or any other planetary surface," Heinz said.
O-PTIR, unique to JPL, has already supported other NASA projects. In 2024, it helped verify the cleanliness of the Europa Clipper spacecraft before launch. Following its success with Mars-analog samples, the team is now collaborating with NASA's Mars science group to study algal microfossils, often used as rover analog targets.
Research Report:Application of optical photothermal infrared spectroscopy (O-PTIR) for future returned Mars samples
Related Links
Review of Scientific Instruments
Mars News and Information at MarsDaily.com
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