The dust on the moon can often appear to be floating above the surface. This phenomenon was first photographed by the Surveyor program in the 1960s. This apparent defiance of gravity is caused by the photoelectric effect and electrostatic levitation.
http://www.mts.net/~patryluk/pictures/22mar02_moon_xt8_25mm.jpg
First, light, or photons, from the sun hit the moon dust particles. Through the photoelectric effect an electron is ejected from the particle, giving it a positive charge. Then, electrostatic levitation causes the particles that have been charged to repel each other. Because there is no atmosphere on the moon, and the effects of gravity are much less than on Earth, some of the particles are repelled upwards. These particles can reach heights of up to a few kilometers. Particles that reach a significant height can also create a wave-like fountain effect across the surface.