NASA is tracking the comet's journey with the SDO (Solar Dynamics Observatory) spacecraft which will off-point at three different positions as Comet ISON moves through perihelion. The comet, which is traveling at more than a million kilometers an hour, is scheduled to reach its critical phase around the Sun between 12:45 pm and 1:00 pm ET (9:45 am and 10:00 am PT). Go here to watch near realtime images and movies. And here's a live feed:

Image Credit: ESA/NASA/SOHO.