NASA's Perseverance rover carries small swatches of spacesuit material to test how Martian dust affects equipment destined for human missions. After 1,645 Martian days, the swatches showed little visible wear, suggesting Martian dust may be less abrasive than lunar dust encountered during Apollo missions.
Scott VanBommel, a research assistant professor of earth, environmental and planetary sciences at Washington University in St. Louis, led the study published in the Proceedings of the National Academy of Sciences. Co-author Abigail Knight, a staff scientist, helped conceptualize and conduct the analysis.
The researchers found that Martian dust particles are much smoother than lunar dust grains. "The particles in the Martian atmosphere have been blowing in the wind for potentially billions of years, so they tend to be well rounded, like pebbles in a river," VanBommel said.
However, Martian dust presents different hazards. Some particles measure as small as 100 nanometers across. These ultrafine particles concern engineers because on Earth, particles of similar size from pollution can penetrate deep into lungs and enter the bloodstream.
The chemical composition adds another risk. Unlike lunar dust, Martian dust contains perchlorates and other potentially toxic compounds. It is also enriched in sulfur, iron and silica. VanBommel noted that brief exposure may not seriously threaten astronauts' health, as risk depends on dose and duration.
The electrostatic properties of Martian dust likely cause it to preferentially adhere to some surfaces, Knight added. Mission planners will need to account for these properties when designing habitats, spacesuits and air filters.