Volcanic Lightning

This has got to be one of the most amazing photographs I've ever seen! This was taken during a lightning storm while a volcano was erupting.

Quote from National Geographic:

The mingling of lightning and ash seen above may be a "dirty thunderstorm."

The little-understood storms may be sparked when rock fragments, ash, and ice particles in the plume collide to produce static charges—just as ice particles collide to create charge in regular thunderstorms.

You can read the entire story on National Geographic Online here.