Moon Dust

by C. Zaitz

I’ve been thinking a lot lately about dust. Not just the dust that accumulates on the piano or the blinds. Not even the dust mixes with my shedding dog’s hair and ends up big as my fist, rolling across the hardwood floor. No, I’ve been thinking of far away dust, the kind of dust that sheaths the moon.

I have the privilege of working with some students who are involved in special projects. One student is trying to measure the electrical charge of dust that has been exposed to ultraviolet light. She chose this project because it seems that dust on the moon is very clingy. Astronauts who went to the moon and walked around got very dirty, very quickly. As soon as they stepped on the dust, it jumped onto their spacesuits and clung for dear life, almost as if the little dust particles had been waiting for billions of years for a ride to earth and finally it saw the opportunity. She wanted to see how charged dust can get, even here on earth. In that process we’ve both been learning a lot about dust. It’s not very sexy, but it’s pretty important.

Moon dust has some interesting properties. It’s not like the soft dust we find around the house. That dust is made of flakes of skin, pet dander, dirt particles and lint, among other things. Moon dust, however, is craggy and jagged. It’s made when asteroids hit the moon and pulverize rock. There’s nothing soft about moon dust. It’s so sharp that it cut through the seals on containers used to carry it back to earth. You wouldn’t want to step on a dust ball made of moon dust.

One of the problems with moon dust, and even dust on Mars, is that it tends to cling to everything. Scientists have different ideas why. One of the most popular ideas is something we experience all the time; static electricity, or better said, a difference in charges. Think of that dust that collects on your TV screen. The screen gets charged when it’s on, and the neutral dust gets attracted to it. Now think of the moon’s surface. Radiation from the sun knocks electrons off the dust and the particles become charged. Once an astronaut walks through the dust, the difference in charge makes the dust veritably leap onto the astronaut’s spacesuit. Since the dust is so caustic, in time it can cut and poke into the skin of the spacesuit, which is the only thing protecting the astronaut from certain death in the lunar environment. The dust is carried into the lunar lander and can get into sensitive equipment, with the potential of causing disaster.

Studies on how to combat the “stickiness” of the dust and the potential harm from it ended with the Apollo missions, but the rovers on Mars are still hampered by Martian dust as it covers their solar panels and gets into the working parts. It turns out that lowly dust can be a very important issue in future space travel. It could also be a key into understanding how the solar system formed, since current theories imply that the sun and planets coalesced out of space dust and gas. Dust has been around a long time. Perhaps with further study, we will know how to deal with moon dust by the time we get there in 2018. I know I wouldn’t want moon dust ruining my trip to the moon!

Until next week, my friends, enjoy the view.