Take a look at this amazing composite photo from NASA, called "Earth at Night." Sort of puts things in perspective, don't it?

I've only just discovered the NASA web site. I was all set to start a new thread, but I noticed it has already been mentioned here, so I just refreshed this old thread.

NASA has an Astronomy Picture of the Day as well as an Archive going back to 1995.

If you find any more cool pictures, post a link to them here.