In Pictures: Fabulous space photos from NASA’s Hub...
This image shows a ghostly ring of dark matter in a galaxy cluster designated Cl 0024+17. Astronomers call the ring one of the strongest pieces of evidence to date for the existence of dark matter, an unknown substance thought to pervade the universe. Astronomers suggest that the ring was produced from a collision between two gigantic clusters.
In Pictures: Fabulous space photos from NASA’s Hubble telescope