Comet ISON is about to put on a show.

Scientists around the world are watching as ISON streaks, ever-faster, towards the sun.

NASA has been studying ISON since December, when it was more than 800 million kilometres away.

Experts are calling Comet ISON as “the comet of the century.”

What is a comet? Here’s how astrophysicist Julie Abraham describes a comet: “It’s basically a big ball of dirty ice in orbit around the sun that gradually melts or burns up, spewing out debris and water in a plume blown out behind it.”