The wind picks up momentarily, and a pillar of swirling dust forms and moves across a barren landscape. It's a scenario that can take place here in the deserts of Earth and in the harsh landscape of Mars.
Though they're usually harmless on Earth, dust devils can grow to formidable sizes and pose a serious risk to future robotic and crewed missions on the red planet — not least because most of these will rely on solar panels that must remain clean to operate.
That's why Louis Urtecho of NASA JPL and the California Institute of Technology is building the software required to detect dust-devil-induced pressure signatures automatically," a press statement reveals.
Dust devils have revived and killed past NASA missions
Dust devils on Mars could play a massive role in the Martian climate, and they can reach sizes of up to 1,600 meters in diameter, meaning they could potentially affect plans for building habitats on Mars.
In July last year, NASA's Mars Perseverance rover used its Navigation Camera (M2020) to capture images of three dust devils in the vicinity of its landing site on the red planet's ancient, dried-up lakebed, the Jezero Crater. The photos, taken so close to the Perseverance rover's landing site, show that, though the phenomena are difficult to predict and capture, they are not uncommon.
"The abundance of dust devils on Mars could have implications for the lifetimes of many missions. Dust devils have already played a role in past missions," Urtecho explained in the press statement. "Opportunity and Spirit rovers' lives were extended because friendly dust devils blew dust off their solar panels. But Opportunity eventually succumbed to a global dust storm on Mars, showing the importance of dust loading in the atmosphere."
Developing a dust devil detector
Due to the fact they can be dramatically shortlived — most dust devils on Earth last for only a few seconds — and are hard to find and study, Urtecho and his team set out to explore dust devils on Earth. Once they collected enough data, they applied their findings to computer models and developed a dust devil detector.
Using microbarometer data collected from the Mojave desert in California, the team designed an algorithm to look for the pressure activity that indicates a dust devil is active. The algorithm is based on the fact that the vortices have a significant drop in pressure near their centers. The scientists explained that their pressure also fluctuates over time, making the data look like an electrocardiogram (EKG) signal.
"The hope is that with our dust devil detector, we will be able to learn more about the formation characteristics of convective vortices and how they move across various landscapes," Urtecho explained. "This will improve the accuracy of Martian weather models, which has a direct impact not only in understanding dust cycles on Mars and the role they have played in its evolution but also the operation of future robotic and possibly crewed missions."
