NASA’s Perseverance rover has provided measurements of Martian dust particles small enough to raise concerns for future crew exposure. Researchers identified particles approximately 100–200 nanometers across on spacesuit samples and calibration targets, extending knowledge of dust below the sizes characterized by earlier surface measurements.
The study, published in PNAS, examines fine and ultrafine dust using analysis and modeling of X-ray fluorescence data. Publisher-deposited metadata records online publication on October 26, 2026. The findings concern particle properties and potential exposure hazards, rather than measured illness in astronauts.
Using Calibration Targets to Examine Dust
Perseverance carries spacesuit-material samples on the calibration target for its SHERLOC instrument. Calibration targets provide known materials against which instruments can check their measurements. Exposure on the rover also allows researchers to examine how dust accumulates on those surfaces.
According to NASA’s explanation of the research, the PIXL X-ray instrument supplied the dust measurements. Its own calibration target includes Teflon and basaltic glass. Because the Teflon does not contain elements PIXL can directly detect, elemental signals from that surface reveal material deposited on it.
The study’s abstract describes the dust as silicate material enriched in phosphorus, iron, and sulfur. It reports particles accumulating on materials comparable to potential outer layers of crew systems, connecting the measurements to equipment astronauts might use.
Small Particles Behave Differently
Earlier Mars measurements characterized coarser particles at approximately 3 micrometers and above. The study addresses finer material, including particles near one-tenth of a micrometer. A nanometer is one-billionth of a meter; 100 nanometers equals 0.1 micrometer.
Particle size matters because sufficiently small airborne particles can penetrate deep into the lungs. Establishing the presence and composition of such particles helps identify an exposure pathway, but does not by itself quantify the health consequences of a future astronaut’s exposure.
NASA reports that dust accumulation differed between materials and that the finest particles remained attached through extended rover operations. Static electricity appears to influence which particles adhere to particular surfaces. These observations make material choice relevant to controlling the dust carried toward living spaces.
Implications for Suits and Habitats
The findings can inform investigations of protective coatings, spacesuit outer materials, and methods for reducing dust transfer into habitats. NASA identifies suitports and dual-chamber airlocks as approaches that could help keep contamination outside occupied areas.
The authors recommend more complete laboratory characterization of Martian dust to prepare crew-support systems. That work would connect the measured particle properties with tests of exposure, material performance, and removal methods. The study provides evidence for those evaluations without establishing a new astronaut exposure standard.
