Comet C/2001 Q4, also known as NEAT, emits a blue-and-purple glow as it moves through the cosmos in May 2004. Its coma, or head, and a portion of its tail are visible in this shot, ...

In this Hubble Space Telescope composite image taken in April 2013, the Sun-approaching Comet ISON floats against a seemingly infinite backdrop of numerous galaxies and a handful of foreground stars.