: Comet's Tail Ripped Off

On April 20, 2007, Comet Encke had just dipped inside the orbit of Mercury, perilously close to the sun, when a solar eruption struck and literally tore the comet's tail off.

This surely has happened to comets before, but for the first time in history a spacecraft was watching. NASA's STEREO-A probe recorded a fantastic movie of the collision

http://science.nasa.gov/headlines/y2007/01oct_encke.htm

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Probably an evolutionary adaptation.
If a predator, like a Cosmic Space Dragon, grabbed the comet by the tail, the comet could safely escape.