Pretty Proof
Here's a nice page that is touted as a proof for the existence of dark matter. Dark matter and dark energy have been a hypothetical crutch leaned on by astrophysicists to explain some of the properties of the universe. Basically, the matter and energy that we can detect in the universe don't add up to what's required for it to behave as it does (e.g., it's pushing itself apart at such a rate that can only be explained by undetectable energies). Here is some evidence the crutch may actually be a new limb. It rides on the observation that the hot gases of the recently collided galactic clusters shown below are where most of the visible mass of the clusters has been shifted by the collision.
It's all so silly, really. If we just recognize that dark matter is the presence of The Flying Spaghetti Monster, and dark energy the will of HIS word, we wouldn't have to spend all that money and effort on research, we could all go home and read whatever version of the bible is the One True one, sing our hymns and be content.
Unless you were some kinda Deist and don't go for that teleological mumbo jumbo. Logos, d00d.