Comets have fascinated, even terrified us for thousands of years. This year, a particularly massive chunk of ice and rock is hurtling our way, an object that will fascinate billions and should create the space show of the century. Right now Comet ISON, somewhere between 1 and 10 kilometers in diameter, is just beyond the orbit of Jupiter. As it races past us toward the sun it should develop a tail that will light up the skies brighter than a full moon. In this exciting special, NGC teams up with scientists all over the world as they follow a once-in-a-lifetime event and shoot breath-taking images of the sun-grazer comet. Bringing audiences up close and personal with one of stargazing's most spectacular displays, Comet Ison reveals what the comet is made of, how it behaves and how it marks the latest chapter in the fascinating relationship between comets and humankind.