Spacesuit Swatches on Mars Show Dust May Be Gentler but Toxic

Martian dust looks less likely to chew through spacesuits than the sharp grit on the Moon, but it carries toxic chemicals and sticks stubbornly to surfaces, according to a new study based on NASA's Perseverance rover. Universe Today reported that the findings point to a need for careful astronaut training and equipment design before people go to Mars.

Small swatches of spacesuit material that ride on Perseverance have been exposed to the Martian atmosphere continuously, and they showed little visible wear after 1,645 Martian days, known as sols.

How researchers tested the dust

The work was led by Scott VanBommel, an assistant professor at Washington University in St. Louis, together with staff scientist Abigail Knight. Both are fellows of the McDonnell Center for the Space Sciences. Scientists from the United States, Canada, Australia and Europe also took part, along with researchers from NASA's Jet Propulsion Laboratory and the NASA Johnson Space Center.

The team studied the swatches with the rover's Planetary Instrument for X-ray Lithochemistry, or PIXL. They also used a method VanBommel developed to estimate the size of individual particles in the PIXL data. Universe Today said this gave the first direct characterization of fine and ultrafine particles in the Martian dust.

Smoother grains, but a toxic mix

The particles on the swatches were much smoother than the jagged grains found on the Moon. The report says that is likely because Martian dust has been blown around by wind for potentially billions of years, which rounds the grains much like pebbles in a river. As a result, Martian dust may be less abrasive to equipment and less irritating to the lungs than lunar soil.

The chemistry is a different story. The PIXL data confirmed that the dust contains perchlorates and other toxins, along with high levels of sulfur, iron and silica. Some ultrafine particles measured as little as 100 nanometers across. On Earth, particles that small usually come from smoke and air pollution, and they can sink deep into the lungs and enter the bloodstream. Combined with the toxic chemistry, that raises the health concern.

The dust is also electrostatically charged, as lunar dust is. Knight said the charge is likely making the dust cling to some surfaces more than others.

Why it matters for future crews

Apollo astronauts found that lunar dust followed them back into their landing modules, where it degraded mechanical joints and seals and caused breathing problems. Mars missions face a similar risk. Astronauts will move in and out of vehicles and habitats regularly, and small amounts of dust will probably be carried inside, where nobody is wearing a spacesuit. If that dust is left unchecked, Universe Today said, it could become a growing health hazard.

Dust storms add to the challenge. They range from small whirlwinds that happen daily to global storms that occur about once every 3 Martian years, or roughly 5.5 Earth years, and cover the whole planet. Because Mars has such a thin atmosphere, the storms do not produce much physical force. The report says the danger comes from what the dust does to instruments, machine parts and people's health and safety.

The study's message is not that Mars is off limits. The level of risk depends largely on the dose and the length of exposure, and the report says proper mitigation can keep both low enough to avoid a significant threat. Mission planners are expected to weigh the findings when they design spacesuits and habitat infrastructure.

What rovers have already taught engineers

Rovers have operated on the surface of Mars continuously for more than 20 years. Universe Today noted that these missions have also served as test beds for technologies that human explorers will need, in addition to revealing the planet's geological history. The Perseverance swatches are a direct example: a piece of future equipment tested in real Martian conditions years before any astronaut arrives.

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Around Prague, based on reporting by Universe Today