of alien dust and electrostatics

The most dangerous thing about living on the Moon isn't the radiation. It's the sharp, electrostatic alien dust...

Illustration by John Hrubesch

Moon dust looks calm, gray and featureless. That is until you disturb it and a blast of this sharp, abrasive powder hits you right in the visor. Lunar regolith is more like our volcanic ash than anything else and eons without moisture make it so dry, it clings to anything and everything by electrostatic attraction. On future Moon bases, this dust will get into machinery and get tracked into crew modules. If its levels aren’t carefully managed and kept to a safe level, this microscopic hazard could cause some serious health problems.

So how exactly do you manage this unruly and dangerous alien powder? A previously lost data set from some experiments done by Apollo, shows that lunar regolith’s stickiness is related to the angle of the Sun in the sky. When our parent star’s ultraviolet and X-rays bombard the dust during the lunar day, the tiny particles as wide as the human hair pick up a positive charge and cling to any surface on which they’re deposited by… oh say the exhaust from a spacecraft or a bouncing astronaut. But when the Sun is at an angle of 45 degrees or lower, the bombardment eases and the regolith loses some of its charge, allowing the lunar gravity to pull the dust down from vertical and angled surfaces.

Knowing that the Sun’s rays give Moon dust its cling gives us an important consideration when designning a potential lunar outpost. Not only does it have to support a crew, it should also be able to keep a good area around it in the shade. This study also gives us something to consider when it comes to Mars. Martian topsoil is also very dry and abrasive and the thin atmosphere, a hundredth of the Earth’s, isn’t much of a barrier for UV and X-ray radiation. Could the Sun give it an extra static charge as well? Of course on Mars, we have windy days that can clean the dust off solar panels and other equipment, but astronauts on a Martian outposts might still need to get an anti-static brush for equipment that weathered a dust storm.