On Nov. 18-19, two comets (ISON and Encke) are going to fly by the planet Mercury in quick succession. NASA's MESSENGER spacecraft will have a front-row seat for the rare double encounter.
FULL STORY: http://science.nasa.gov/science-news/science-at-nasa/2013/15nov_twocomets/
VIDEO: http://www.youtube.com/watch?v=v9Wzlu5quTU
