Watch this video clip of some white dots moving against a black background. It is extraordinary, but only if you know what you're looking at.

It's a star, whipping around the very center of our galaxy. Notice that you can't see the thing that it's whipping around. That's because it's a black hole, at the very center of our galaxy. This video clip pretty much confirms that there is a black hole at the center, which can be determined not only by the fact that you can't see it, but the speed at which the star whips by it. They estimate its mass to be about two million times that of our sun.

I had always thought that the center of the Milky Way was too dusty to see into; I don't know how they did it (though the answer seems to be "adaptive optics"). Notice the numbers on the top left; they indicate the year that each frame was taken, so you're looking at a ten-year time-lapse. And at this distance, it didn't just happen; you're looking at a star passing by a black hole about 28,000 years ago. Boggles the mind!