Transcription: A comet starts out as a chunk of dirty ice orbiting the Sun. Something perturbs its orbit, like a collision with another chunk of ice, and that causes it to get into an orbit that brings it close to the Sun. As the comet gets closer to the Sun, heat from the Sun starts causing evaporation of the things that are locked in the ice. That causes the chunk of ice, called the nucleus, to be surrounded by a bright glowing coma. That coma eventually stretches into a tail, which can often be seen seen glowing brightly in the night sky.
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