This 360-degree panorama from NASA’s Perseverance Mars
rover shows Neretva Vallis, the dusty, long-dried river channel that cuts
through the western rim of Mars’ Jezero Crater.
NASA/JPL-Caltech/ASU/MSSS
Over 1,645 Martian days, NASA’s Perseverance Mars rover measured the fine
and ultrafine Martian dust particles found clinging to samples of spacesuit
materials that are carried aboard the rover, including some that are small
enough to penetrate the lungs and enter the bloodstream. The findings will be published Tuesday, Oct. 27, in the Proceedings of the National Academy of
Sciences and could inform spacesuit and habitat design, dust-removal
procedures, and crew health standards for future NASA missions to Mars.
“NASA has a long history of turning
challenges into workable solutions and of finding creative ways to use the data
that we have to answer questions beyond what it was originally collected for,”
said Lindsay Hays, acting director, Planetary Science Division, NASA
Headquarters in Washington. “Dust has been a surface-exploration challenge
since the Apollo program. Perseverance is giving our engineers and flight
surgeons measurements they can use to improve our existing designs well before
the first American astronauts arrive on Mars.”
Lunar dust scratched visors,
degraded outer spacesuit layers, and damaged their seals during NASA’s Apollo
missions, and some crew members reported symptoms similar to hay fever.
Rounded by wind-driven collisions
with other particles, dust grains on Mars are less abrasive than those on the
Moon. They also are enriched in sulfur, chlorine, and iron and contain more
silica than lunar dust. Regional and global dust storms on Mars can keep the
grains recirculating throughout the atmosphere as well.
The rover carries a set of five
samples of spacesuit material. The swatches, each three-quarters of an inch (20 millimeters)
square, are part of a calibration target used to test the settings of SHERLOC (Scanning Habitable Environments with Raman and
Luminescence for Organics and Chemicals), an instrument on Perseverance’s
robotic arm. The calibration target for another instrument that provided the
dust measurements, called PIXL (Planetary Instrument for X-ray Lithochemistry),
carries a sample of Teflon and of basaltic glass.
Because Teflon contains no elements
that PIXL can directly detect, whatever elemental signals the X-ray
spectrometer picks up from that sample comes from dust resting on it.
The team also analyzed swatches of
Teflon and Vectran, two materials used in spacesuits, on SHERLOC’s calibration
target. NASA sent the swatches to Mars to study how spacesuit materials hold up
on the planet’s surface.
“Perseverance’s main job is to
search for signs of ancient microbial life, but the mission was also designed
to help prepare for human explorers. That effort includes technology
demonstrations like MOXIE (Mars Oxygen In-Situ Resource Utilization Experiment)
and Ingenuity, as well as the spacesuit samples,” said Katie Stack
Morgan, Perseverance’s project scientist at NASA’s Jet Propulsion Laboratory in
Southern California.
Fine, ultrafine
While earlier measurements on Mars resolved dust particles down to about 3 micrometers across, PIXL detected two categories of even smaller particles: fine particles measuring less than 2.5 micrometers (a human hair is about 70 micrometers wide) and ultrafine particles around 100 nanometers (about 700 times thinner than a human hair). Particles on PIXL’s Teflon target and SHERLOC’s Vectran swatch averaged about 2 micrometers. On PIXL’s basaltic glass and SHERLOC’s Teflon swatch, dust particle sizes ranged down to about 100 to 300 nanometers.
This annotated composite image shows the location on
NASA’s Perseverance of the calibration target for rover’s SHERLOC (Scanning
Habitable Environments with Raman & Luminescence for Organics and
Chemicals) instrument. At right is a close-up of the calibration target.
NASA/JPL-Caltech
Static electricity appears to determine which size dust particles stick to
which surface. Dust grains become charged as they collide in the air, and
different materials on the calibration target attract grains of different
sizes. The finest particles stayed attached through years of driving and
drilling. Organic polymers like SHERLOC’s Teflon spacesuit sample are common in
the outer layers of spacesuits, and the results show they readily collect fine
dust.
The study also found that some
materials hold less dust than others, which could guide future choices of
materials and protective coatings 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 inside astronauts’
living quarters.
“The existence of Mars dust at
these ultrafine sizes has been predicted for a long time, and PIXL gave us the
chance to measure it directly on Mars,” said Scott VanBommel, a Perseverance
scientist at Washington University in St. Louis and the paper’s lead author.
“The larger clumps, the Martian dust bunnies, get shaken off over time. But the
smallest particles stay behind, and those are the ones that pose the greatest
challenge for human support systems.”
Chemically, the dust matches the
iron- and sulfur-rich composition that earlier missions measured. The PIXL
instrument also found the dust to be enriched in phosphorus and detected signs
of calcium sulfate.
Protecting crews
On Earth, airborne particles, or
particulate matter, below 2.5 micrometers (that is, fine particles) are tied to
a range of negative health effects because they can penetrate deep into the
lungs and enter the bloodstream. Studies have shown that ultrafine particles
(those no larger than 100 nanometers) can travel from the nasal cavity to the
brain along the olfactory nerve.
Martian dust is composed
predominantly of silicate minerals and carries chemically reactive compounds,
including perchlorates that can disrupt thyroid function and reactive iron that
induces cellular damage. Scientists believe that the health risks of Mars dust
depend on the quantity of dust and length of exposure.
The PIXL results are the first
on-site measurements of fine and ultrafine particles on Mars, and this research
can inform broader efforts to refine indoor dust-exposure limits for
astronauts, develop safe habits, and establish ways to remove dust while exploring
Mars.
NASA is already working on
solutions to extraterrestrial dust hazards, using ground test facilities and
lunar missions as proving grounds for future Mars explorers. In March 2025, the
agency tested an Electrodynamic Dust Shield, which used electric fields to clear lunar regolith
from glass and thermal radiator surfaces on the Moon. Developed at NASA’s
Kennedy Space Center in Florida, it landed on the Moon aboard Firefly
Aerospace’s Blue Ghost Mission 1. At NASA’s Johnson Space Center in Houston,
engineers at the Lunar Development and Test Facility use vacuum chambers and lunar regolith simulant to
test spacesuit components, mechanisms, and a Handheld Lunar Electrostatic Dust
Mitigation tool ahead of Artemis missions to the lunar surface.
More about Perseverance
Managed for NASA by Caltech, JPL
built and manages operations of the Perseverance rover on behalf of the
agency’s Science Mission Directorate as part of NASA’s Mars Exploration Program
portfolio. NASA JPL also built PIXL and SHERLOC.
To learn more about Perseverance visit: https://science.nasa.gov/mission/mars-2020-perseverance
