Perseverance finds ultrafine Mars dust clinging to spacesuit materials

Martian dust particles small enough to penetrate the lungs are clinging to samples of spacesuit material carried by NASA’s Perseverance rover, according to a peer-reviewed study published this week in the Proceedings of the National Academy of Sciences (PNAS). The measurements, gathered over 1,645 Martian days, could inform spacesuit and habitat design, dust-removal procedures and crew health standards for future missions to Mars, NASA said on Oct. 26.

The paper, titled “Fine and ultrafine Martian dust presents additional risks for future crewed missions to Mars,” lists 35 authors and is led by Scott J. VanBommel, a Perseverance scientist at Washington University in St. Louis. It is published open access under a Creative Commons license.

How the dust was measured

The rover carries five samples of spacesuit material, each three-quarters of an inch (20 millimeters) square, on a calibration target used to test the settings of SHERLOC, an instrument on Perseverance’s robotic arm. The dust measurements came from another instrument, the Planetary Instrument for X-ray Lithochemistry (PIXL), whose own calibration target carries a sample of Teflon and one of basaltic glass. The team also analyzed swatches of Teflon and Vectran, two materials used in spacesuits, on SHERLOC’s target.

Earlier measurements on Mars resolved particles down to about 3 micrometers, according to NASA. PIXL detected fine particles below 2.5 micrometers and ultrafine particles of around 100 nanometers, about 700 times thinner than a human hair. Particles on the PIXL Teflon target and the SHERLOC Vectran swatch averaged about 2 micrometers, while those on the PIXL basaltic glass and the SHERLOC Teflon swatch went down to roughly 100 to 300 nanometers. The paper’s abstract reports particles as small as 100 to 200 nanometers.

The dust is rich in iron and sulfur, matching results from earlier missions, and PIXL also found it enriched in phosphorus and detected signs of calcium sulfate, NASA said. The authors describe it as a mafic silicate enriched in phosphorus, iron and sulfur. Static electricity appears to determine which particle sizes stick to which surface: grains become charged as they collide in the air, and different materials attract grains of different sizes. The finest particles stayed attached through years of driving and drilling.

“The larger clumps, the Martian dust bunnies, get shaken off over time,” VanBommel said. “But the smallest particles stay behind, and those are the ones that pose the greatest challenge for human support systems.”

Why it matters

On Earth, airborne particles smaller than 2.5 micrometers are tied to a range of negative health effects because they can penetrate deep into the lungs and enter the bloodstream, NASA noted, and studies have shown that ultrafine particles can travel from the nasal cavity to the brain along the olfactory nerve. Martian dust is mostly silicate minerals but carries chemically reactive compounds, including perchlorates that can disrupt thyroid function and reactive iron that induces cellular damage, according to the agency. The authors argue that such respirable particles pose a potential systemic health risk to future crews.

The findings also bear on engineering. Some materials held less dust than others, which NASA said could guide choices for spacesuits and habitats. Designs such as suitports, which let astronauts enter a suit attached to the outside of a habitat, and dual-chamber airlocks could reduce how much dust gets into living quarters. “Dust has been a surface-exploration challenge since the Apollo program,” said Lindsay Hays, acting director of the Planetary Science Division at NASA Headquarters. In March 2025, NASA tested an Electrodynamic Dust Shield that used electric fields to clear lunar regolith from glass and thermal radiator surfaces on the Moon.

The spacesuit swatches were flown with this kind of preparation in mind. Perseverance’s main job is to search for signs of ancient microbial life, said Katie Stack Morgan, the rover’s project scientist at NASA’s Jet Propulsion Laboratory, but the mission was also designed to help prepare for human explorers through technology demonstrations such as the Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE) and the Ingenuity helicopter, as well as the spacesuit samples.

The caveats

The study measured dust that had settled on calibration targets and material swatches mounted on a rover, not airborne dust or the amount a person would breathe, and it did not test health effects directly. The authors call for Martian dust to be studied in laboratories on Earth to help prepare for crewed surface missions.

Corrections and tips: email the editor using the address on the Contact page.