From SpaceWeather.com:

This week’s full Moon (Oct. 25-26) is the biggest full Moon of 2007. It’s no illusion. Some full Moons are genuinely larger than others and Thursday night’s will be as much as 14% wider and 30% brighter than lesser full Moons we’ve seen earlier this year. Check http://spaceweather.com for the reasons why.

And:

Astronomers in Japan and Europe report that Comet 17P/Holmes is undergoing a spectacular eruption. The 17th-magnitude comet has brightened by a factor of five hundred thousand or more during the past 24 hours becoming a naked eye object in the evening sky. This may signify a breakup of the comet’s core or a rich vein of ice suddenly exposed to sunlight–no one knows. Look for a yellow 2.5th-magnitude fuzzball in the constellation Perseus after sunset. (“2.5th magnitude” means a little dimmer than the stars of the Big Dipper.) At present the comet looks more like a star than a comet; it does not have a discernable tail, but it might grow one as the outburst continues. Visit http://spaceweather.com for a sky map, photos and updates.