ISON entering the sun's outer plasma atmosphere on 27 - 28 Nov 2013 as streamed & updated live by NASA/ESA SoHo spacecraft.
Turkey is not the only thing roasting today. Comet ISON is streaking to its closest approach by the Sun today, where the itty-bitty nucleus, thought to be less than a mile across, may experience surface temperatures as high as 2800° C or about 5000° F! If ISON survives that ordeal, there's a good chance residents in the northern hemisphere will have a clear view of the colorful leftovers boiling off the comet's nucleus into space right through Christmas, as it blazes past Earth bound for interstellar space. Bad Astronomer Phil Plait is on the case:
The fact that ISON is blooming means it’s getting very bright, probably around magnitude 0.5, about as bright as Mercury as seen from Earth. This is expected, and a good sign! It means gas is pouring off the solid nucleus of the comet and being illuminated by the intense light of the Sun. If it manages to hold itself together, ISON will get even brighter over the next day, and the pictures from SOHO will be spectacular.
Don’t forget: I’ll be participating in a NASA Google+ Hangout Thanksgiving day at 18:00 UTC (I’ll be on at 18:30 for an hour), talking about the comet with several scientists, and showing live images from SOHO and other observatories. Stay tuned to the blog and I’ll have the link and an embedded video so you can watch it live. The Planetary Society also has links where you can get more ISON info, and the Comet ISON Observing Campaign is another great source of news.
See also discussion and links in Caddis Fly's diary here.
Update 1 PM Central: BTW folks, if ISON does break up as it may be doing right now (Perihelion just passed and the comet or remains are now beginning the outward bound leg of the journey) we may get superb spectroscopic data of the rocky or metal bits as they vaporize. If so, we'll get to see inside a solar nebula fossil more than 4.5 billion years old, telling us what the earliest stages of planetary formation were like. Not a bad consolation prize for science!