NASA's Perseverance rover has measured Martian dust fine enough to reach deep into human lungs. The dust was clinging to spacesuit material the rover carries. The study is set to be published Tuesday, Oct. 27, in the Proceedings of the National Academy of Sciences.
What the rover found
- Earlier Mars measurements could detect particles down to about 3 micrometers. The PIXL instrument found fine particles under 2.5 micrometers and ultrafine particles of about 100 nanometers.
- For comparison, a human hair is about 70 micrometers wide.
- The samples are small swatches of spacesuit materials, including Teflon and Vectran, on the calibration targets for the SHERLOC and PIXL instruments. The measurements span 1,645 Martian days.
- Static electricity appears to decide which particle sizes stick to which materials. The finest grains stayed attached through years of driving and drilling.
Why it matters for astronauts
On Earth, particles below 2.5 micrometers are linked to health effects because they can get deep into the lungs and the bloodstream, JPL notes. Martian dust also contains perchlorates, which can disrupt thyroid function, and reactive iron.
"The larger clumps, the Martian dust bunnies, get shaken off over time. But the smallest particles stay behind," said lead author Scott VanBommel of Washington University in St. Louis.
The team found that some materials hold less dust than others. NASA says that could guide coatings, suitports and dual-chamber airlocks for future Mars habitats.