NASA Swift spacecraft suggests volatiles, not water sublimation, is powering Comet ISON's early activity.
Comet brightness is difficult to predict, as each comet has its own characteristics that can defy expectations, for better or fo…
NASA describes Comet ISON and suggests its potential--provided it survives sungrazing.
NASA coordinating campaign to view Comet ISON with multiple observatories.
What's the story with these icy interlopers from the depths of the solar system? What can we expect from Comet ISON (C/2012 S1)--sizzle or fizzle?