Will dust prevent us living on the Moon?
If astronauts are ever going to return to the Moon, they must come to terms with the hazards of the lunar environment. To combat a major threat to astronaut health and technology, ESA is conducting a major study of moon dust to determine how dangerous it is and how to counter its effects on humans and machines.
Even before Neil Armstrong set foot on the Sea of Tranquility, scientists and engineers were concerned about the hazards of lunar dust. While rockets like the Saturn V were being tested for the first voyages to the Moon, there was a very real concern that moon dust would present an insurmountable barrier to lunar exploration.
The problem was that no one had a firm idea about what the surface of the Moon was like. Perhaps it was as firm as the great lava flats in Hawaii or Iceland. Or maybe the so-called seas and craters were filled with fine dust hundreds of meters deep in which any spaceship would vanish like a sash weight dropped in the ocean.
But what the Apollo astronauts found was unexpected and equally worrying. Instead of seas of liquid-like dust, they discovered that billions of years of micrometeorite impacts had coated the lunar surface with a fine layer of silicate dust that had a number of disturbing qualities.
For one thing, it was as dry as it's possible to be, and bombardment by solar and cosmic radiation had left the particles with a static electric charge. This made the dust stick to the astronauts' spacesuits as a grayish, black powder that was almost impossible to shift and ended up contaminating both the interior of the Lunar Module and the orbiting Command Module when they returned, making them smell like burned gunpowder.
Worse, the dryness and radiation made the dust chemically active and the particles were so abrasive that they took their toll on the spacesuits, sample containers, and other equipment. As for the astronauts, all 12 of the moon walkers came down with "lunar hay fever" with symptoms like sneezing and nasal congestion that took days to subside after returning to Earth.
Now, an international team of a dozen scientists will examine the long-term effects of exposure to moon dust. There are already indications that it could cause serious illnesses, like cancer, but the exact hazards posed by the dust and their implications remain largely unknown.
Silicate dust is already a hazard on Earth, especially for miners or people exposed to dust storms or volcanic eruptions, which can cause a condition called silicosis. But lunar dust is different. The highly active environment of Earth wears down silicate particles, so they become rounded, but moon dust has sharp, jagged edges that make it so abrasive that it wore away at the special outer boots worn by the moon walkers. What this would do to lung tissue can only be imagined at this point.
Another problem is that since the gravity on the Moon is only a sixth of the Earth's, it means that any nano-scale dust inside a spacecraft or habitat would remain suspended in the air for months, producing longer and deeper lung exposure.
According to ESA, one of the biggest hurdles to studying moon dust is that hardly any samples of the real thing is available, so a simulant made from material mined from a volcanic region of Germany is underway. While it's relatively easy to find the proper glass-like minerals, the difficulty is reproducing the abrasiveness and other properties needed to make a proper study.