So, I guess I am a little late on this one, but I found it so interesting. I was searching for a work around of a dead link of a post I did a while back and I came across this amazing interactive visualization from Chrome Experiments.
You have probably heard that the universe is big. Really big. I have talked about how animations and visualizations can be so helpful in aiding understanding (here and here, among other places). This incredible animation is just that; a way to understand the vastness and wonder of our galaxy. Take a guided tour and stop at landmarks like Voyagers 17 light hours location and the seemingly distant Oort Cloud, which is just a house at the end of the street compared to the mind-boggling distance we still have to go to see our galaxy, the Milky Way.
The beauty of this tool is that you, the user, can scroll in and out and click and drag to change your perspective. Furthermore, there are a bunch of stars that you can click on and get little (Wikipedia sourced) tid-bits on it. Very cool as a class intro to space, an interactive addition to a student presentation, or just for fiddling around with when a student has a few minutes to spare.
Please let me know if you have any similar (or different) interactive animations that have some value to teachers.