No matter how often you clean your house, there's just no getting rid of dust. But other than a bit of embarrassment when friends or family drop by, or the occasional sneeze, it's generally not much of a problem.
If people ever live on Mars or the Moon, though, dust could be more than just a problem -- it could be deadly.
On both worlds, the dust could gum up the joints on spacesuits, or mechanical systems like doors. It could act like sandpaper, wearing away surfaces and scratching tender skin. And it could get into sensitive electronics, creating short-circuits. Any of those effects could potentially be life threatening.
Moondust would be nastier than Mars dust. That's because much of it is much more finely ground -- the result of billions of years of pounding by a steady rain of space rock. And much of it consists of tiny bits of glass, which have sharp, jagged edges. Breathing in too much of the stuff could damage a person's lungs.
So colonists on these worlds will need to be extra careful to keep most of the dust outside, and not track it into their living spaces. It's not just a matter of appearances -- it's life and death.
Mars is quite low in the west as twilight begins to fall, a little to the upper right of Venus, the brilliant "evening star." Binoculars will help you find the planet. You won't need any help finding the Moon, though -- it's well up in the south at that hour, passing through the eastern edge of Sagittarius.
Script by Damond Benningfield, Copyright 2010