What's Your Favorite Science Photo?

Science not only answers some of our most basic questions, it also provides us with some truly spectacular photography. Today we want to see your favorites!

It could be a classic, like this shot from NASA's first lunar mission, a new image that you think deserves to be a classic, or even one that you've shot yourself in your lab or backyard.

Tell us in the comments what the image is and why you're a fan.

Image: NASA.