Taking a walk is great for inspiration. There have been numerous studies about how people think more clearly on walks, and how new ideas come to them more frequently while doing so. That’s part of the reason some of the most famous minds in history included a daily walk in their schedule. Just such an inspiration must have happened recently to Nicholas Heinz, a scientist at NASA’s Jet Propulsion Laboratory (JPL) in California. On a hike in Arizona he found a rock that could be used as an analog of a unique one found by the Perseverance rover on Mars – and decided to take it back to his lab to study it.
A more accurate description of the unique rock Perseverance found was a core sample of a larger rock called Cheyava Falls, named after one of the ephemeral waterfalls in the Grand Canyon. The rover drilled a hole in it to take a core sample, which is now called Sapphire Canyon, and holds interesting “leopard-like spots”. On Earth, spots like that are associated with chemical activity by microbes, meaning that Sapphire Canyon might hold a clue to discovering life on Mars.
But for now, it is stuck in a test tube in Jezero Crater on Mars, awaiting a potential pickup from the Mars Sample Return mission. Many scientists don’t really like just waiting to get their hands on new data, or on a sample, so many times they decide to run a simulation, or better yet, find some analog that is more easily accessible.
Video from JPL showcasing the Sapphire Canyon sample. Credit – NASA Jet Propulsion Laboratory YouTube Channel
Dr. Heinz seemed to come across just such an analog while hiking one day in Sedona, Arizona. He noticed a rock with similar spots to those found on Sapphire Canyon, so he packed it in his backpack and took it back to his lab at JPL, hoping to use his lab’s advanced chemical tooling equipment on it as a trial run for a future test on Sapphire Canyon.
He works in the Analytical Chemistry and Materials Development group at JPL, where they have a mission to analyze and work on new materials for space exploration. They also have some pretty cool equipment, including an instrument called an optical photothermal infrared spectrometer (O-PTIR). O-PTIR uses two lasers – one heats up a sample, which causes surface to vibrate according to his structure. A second laser then analyzes how much those vibrations change the structure itself, giving each material a unique chemical footprint.
In tests like these, differentiating between the surrounding rock and the spots that were present in both Sapphire Canyon and Dr. Heinz’s sample of Sedonan basalt is one of the hardest things to do for a scientific instrument. It was also the main purpose of testing the analog rock. The team found O-PTIR to be super effective in differentiating between the two materials, in part because it has very high spatial resolution.
Fraser discusses the original Mars Sample Return mission concept, which is now under threat.
Also importantly, it’s very fast. O-PTIR can be used as a preliminary screening to probe samples quickly, and then allow more detailed analytical devices to concentrate on specific areas of interest. It can also be applied to any type of material, such as lunar regolith or even asteroid sample returns.
Getting the actual Sapphire Canyon sample that inspired Dr. Heinz back from Mars may be tricky though. The Mars Sample Return mission has been going through some very public issues lately, and its future remains uncertain at this point. Someday Dr. Heinz might get his hands on the original sample that he was thinking about when on his hike, but that day might be a long way from now.
Learn More:
American Institute of Physics / Eureka Alert – Studying terrestrial rocks to prepare techniques for Mars
N. Heinz et al – Application of optical photothermal infrared spectroscopy (O-PTIR) for future returned Mars samples
UT – A Look Inside One of Perseverance’s Core Holes
UT – Perseverance Finds its Dream Rock