Unlike Earth, the Moon has no magnetic field to ward off charged particles from the Sun. Solar wind blows directly onto the lunar surface. Researchers have long suspected that electrons in the solar wind become embedded in moondust, causing the dust to "charge up" and giving the Moon a very bad case of static cling.

Strange things can happen when moondust gathers charge. For one, the dust might rise up and, propelled by electrostatic repulsion, rush in a diaphanous wind across the lunar surface. Imagine, dust storms on an airless world with no weather!

But it could be even stranger than that. NASA researchers have discovered that moondust peppered with solar wind electrons gain not a negative but a positive charge. This unexpected and counterintuitive reaction makes it hard to predict what is really happening to dust on moon.
go