This is a diagram of the structure seen around an active asteroid designated P/2013 P5. The NASA/ESA Hubble Space Telescope imaged six dust tails in September 2013. One interpretation is that the asteroid's rotation rate has increased to the point where dust is falling off the surface along the equator and escaping into space. The pressure of sunlight then sweeps the dust into long tails. The entire structure rotates like a wheel.