Some of Mars' dust is far finer than scientists had previously measured, a finding that could influence how future crews protect their habitats and health. Researchers used dust accumulated on materials aboard NASA's Perseverance rover to estimate the size and composition of the particles.
The analysis, published in the journal Proceedings of the National Academy of Sciences, found particles averaging about 140 nanometers on a glass calibration target and around 300 nanometers on a Teflon spacesuit-material sample. Some were estimated to be just 100 to 200 nanometers across--hundreds of times thinner than a human hair.
Dust collected during years on Mars
Perseverance landed in Jezero Crater in 2021. Researchers examined dust that had settled on calibration targets and test patches of spacesuit fabrics carried by the rover. By comparing measurements of clean materials with later readings, they could distinguish the dust's chemical signal from that of the surfaces beneath it.
The fabric samples gathered particles differently: Vectran, a strong synthetic fiber, held more dust between its woven threads, while Teflon collected less overall but retained smaller particles. After 1,645 Martian days, the test materials showed little visible wear.
Implications for future crews
Very small particles could be a concern if they enter a pressurized habitat and are inhaled, potentially reaching deep into the lungs. Martian dust is also known to contain iron and silica, and earlier research has identified compounds such as perchlorates. The new study detected phosphorus-rich fine dust, though its effects on human health remain uncertain.
NASA has set limits for dust exposure inside habitats, but more research is needed to establish safe levels for Martian particles. Possible engineering measures include external spacesuit docking, double airlocks and filtration systems capable of capturing particles smaller than a micrometer.
More precise knowledge of Martian dust could help shape safer habitats and suit designs, an important step toward making sustained human exploration of Mars more feasible.
