I have always found the Hubble deep field photograph, apparently Hubbles most important photograph, very interesting.
For those of you who don't know, it's a long exposure or series of long exposures taken over many months of an otherwise completely empty and black region of space.
I was reading some info on it from the UK physicist Brian Cox, and he explains another dimension to it.
When you look at the deep field photograph, you are seeing a true 3D picture. Each galaxy in the picture are vast distances apart. Some relatively near, some almost the entire edge of the galaxy away. All the photons that came to make up the picture set off from different times and locations and you are looking back in time when you look at each galaxy. When the photons set out on their journey, our solar system hadn't even formed, nor life to build the equipment to receive it. Many lifeforms did eventually evolve and go extinct. Eventually man evolved and was able to build machine to take us into the sky to take these pictures.