These Tiny Particles Could Be A Big Problem For Future Mars Astronauts

Of all the challenges of sending people to Mars, there's one tiny problem which you might not think about but which could be a huge challenge: dust. The Martian surface is covered in a dusty material called regolith, and scientists investigating this material have concerns about how it could affect the health of any future visitors there.

This is assuming that a group of astronauts could safely launch in a powerful rocket, travel to Mars over a period of months, land on the planet, and set up shelter with food and water, of course. Not to mention the challenges of doing that whole process in reverse to get home again at the end of their mission.

But in the middle of that, explorers will have to spend time on the Martian surface, and that means they will be exposed to dust, so it's worth considering what the health effects of that could be, and how astronauts could be protected from it.

"This isn't the most dangerous part about going to Mars," said lead researcher Justin Wang of the Keck School of Medicine at the University of Southern California in Los Angeles, in a study published in GeoHealth. "But dust is a solvable problem, and it's worth putting in the effort to develop Mars-focused technologies for preventing these health problems in the first place."

When astronauts went to the Moon for the Apollo missions, they found that moon dust was a major problem. The dust caused runny eyes and irritated throats, and there have since been indications that lunar dust is toxic.

The moon dust also got everywhere, coating spacesuits and equipment. Moon dust was particularly bad because there is no atmosphere on the moon, so the dust particles don't get worn down by the wind. Instead, they stay sharp, like shards of glass, and can be dangerous to electronics and spacecraft, as well as people.

The situation on Mars is different, as there is an atmosphere there (albeit a thin one), so Martian dust isn't necessarily very sharp. But there is a lot of it, and that dust can be whipped up into dust storms which can cover the entire planet. When dust is thrown up into the atmosphere, it's going to come back down and cover everything on the surface, from solar panels to habitats to rovers and other equipment.

"You're going to get dust on your spacesuits, and you're going to have to deal with regular dust storms," said study co-author Brian Hynek of the Laboratory for Atmospheric and Space Physics (LASP) at CU Boulder. "We really need to characterize this dust so that we know what the hazards are."

Dust on Mars can be dangerous in the same way that dust on Earth can be. We know that miners on Earth, for example, can get a condition called black lung disease from inhaling coal dust.

Dust is dangerous to inhale because it can include very small particles that are hard for the lungs to expel. And the dust on Mars is thought to be really tiny, at as little as 3 micrometers across, or roughly one-ten-thousandth of an inch.

"That's smaller than what the mucus in our lungs can expel," Wang said. "So after we inhale Martian dust, a lot of it could remain in our lungs and be absorbed into our blood stream."

And that's not the only problem with Mars dust. The regolith on the planet's surface also contains compounds called perchlorates, which are known to be dangerous and cancer-causing here on Earth. Perchlorates are found only in small quantities on Earth, but they could be present in much larger quantities on Mars, where they could cause damage to the pulmonary system.

The authors point out in their research that health problems are particularly difficult to address for Mars missions because astronauts will be so far from home that emergency medical treatment will be much harder. They suggest that future Mars explorers both avoid contact with dust as much as possible and also be given supplements to protect them against these potentially dangerous effects.

"Prevention is key. We tell everyone to go see their primary care provider to check your cholesterol before it gives you a heart attack," Wang said. "The best thing we can do on Mars is make sure the astronauts aren't exposed to dust in the first place."