"Last week Comet Holmes was just another fuzzball you could only see with a telescope--until it suddenly brightened a million times in a few hours. Now, you can easily see it with the naked eye, it's still expanding, and it has even changed color. ..."
When Comet 17P/Holmes was first discovered in 1892, it showed a magnitude change much like its 2007 visit to our neighborhood. Its orbital period is roughly 6.9 years, so it evidently does not traverse a major part of our galaxy.
If you can find the Big Dipper, you should be able to find
Comet Holmes over the next week or so.
All-in-all, this has been a pretty good season for interesting astronomical observations.