The Hubble Space Telescope photographed the never-before-seen tails on Sept. 10, and then again two weeks later.
NASA alternately describes the spinning space rock, designated P/2013 P5, as looking like "a rotating lawn sprinkler" or "spokes on a wheel."
"We were literally dumbfounded when we saw it," said lead investigator David Jewitt of the University of California-Los Angeles. "Even more amazing, its tail structures change dramatically in just 13 days as it belches out dust. That also caught us by surprise."
One possible explanation:
The tails formed through a series of impulsive dust-ejection events. These could have been triggered when the gentle nudge of sunlight spun up the asteroid to the point where dust is falling off the surface and into space. Solar radiation stretches the dust into finger-like streamers.
"It's hard to believe we're looking at an asteroid," Jewitt said.
