What is Moon Dust? – And is it Toxic?

Have you ever wonder about what that Moon Dust or Lunar Soil is, and if it’s toxic? If you do, then please read on. 

During the Apollo Moon missions of 1969-1972, they all share a dirty secret. And its called: Moon Dust. The major issue the Apollo astronauts pointed out was all the lunar dust.

The Dust is rough as sandpaper and fine as flour. Lunar soil or Moondust caused “lunar hay fever” and real problems with the spacesuits.

In this article, I will reveal the secrets behind Moon Dust. Both it’s composition and if it is toxic or dangerous for the astronauts.

Video credit: Smithsonian National Air and Space Museum.

What is The Composition of Moon Dust?

Lunar soil or Moondust is the fine portion of the regolith located on the lunar surface.

And its attributes can vary significantly from those of earthly soil. The physical properties of Moon Dust are essentially the effect of mechanical disintegration of anorthositic and basaltic rock.

It is the result of continual meteoric impacts and continuous bombardment by interstellar and solar-charged atomic particles over the years. 

And the process is largely one of mechanical weathering in which the bits are ground to more powdery size over time. 

Picture showing lunar soil collected by Apollo 17. Credit: Wikipedia.
Picture showing lunar soil collected by Apollo 17. Credit: Wikipedia.

Furthermore, this situation differs fundamentally from terrestrial soil formation. It is, in turn, mediated by the presence of molecular oxygen (O2), atmospheric wind, humidity, and a strong collection of contributing biological processes. 

Some have insisted that the term soil is not accurate in reference to the Moon because, on Earth, the soil is defined as having organic content, whereas the Moon has no organic materials. 

Nevertheless, standard usage among lunar scientists neglects that difference.

Lunar soil or Moon Dust typically refers to only the finer fraction of lunar regolith, which is comprised of grains 1 cm in diameter or less but is often used interchangeably.

The Dust generally suggests it to be even finer materials than lunar soil. Furthermore, there is no official definition as to what size fraction constitutes “dust”; some scientists place the cutoff at less than 50 μm in diameter, and others put it at less than ten μm.

Where Does Moon Dust Come From?

Regolith (/ˈrɛɡəlɪθ/). It is a layer of loose, mixed superficial deposits covering solid rock. And it combines broken rock, dust, soil, and additional related materials.

Furthermore, Regolith also exists on Earth, the Moon, Mars, some asteroids, and other terrestrial planets and moons. So the Moon Dust originates from all the above-mentioned elements.

Video credit: Curious Droid.

Is Moon Dust Toxic?

The toxic effects of Moon Dust have not been studied enough to develop an exposure standard for operations on the Moon’s surface. 

Moon Dust has a high content in the respirable size range. They also have a high surface area that is chemically reactive, and elemental iron “nano-particles” are embedded in the dust grains. 

And these unique properties may cause the respirable Lunar Dust to be at least somewhat toxic to the respiratory system. Still, larger grains can also be abrasive to the eyes and the skin.

When the reactive Dust is inhaled, it can also be expected to react with the pulmonary surfactant and the cells. 

Furthermore, the fine, respirable Lunar Dust could, therefore, be toxic if the astronauts are exposed to the dust during Moon mission operations at a Moonbase.

Picture showing undisturbed lunar soil. Credit: NASA.
Picture showing undisturbed lunar soil. Credit: NASA.

What Color is Moon Dust?

The Dust is grey in color. It originates from the strange attributes of lunar soil. 

Also, the powdery grey dust is formed by micrometeorite impacts that pulverize local Moonrocks into tiny particles. 

The energy from those collisions melts the lunar soil into a vapor that condenses and cools on soil particles, covering them in a glassy shell.

Well, that’s it. I hope you enjoyed this short article.

If you want to learn more about how to view the Moon from a telescope or a pair of binocular, then head over to this interesting article: How To See The Moon: Best Telescope Viewing Tips.

Do you want some more fascinating facts about our only satellite, then head over to this thought-provoking article: Moon Facts – Interesting & Strange Facts About The Moon.

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