This group of galaxies has been nicknamed the "Cheshire Cat" because of its resemblance to a smiling feline. Some of the cat-like features are actually distant galaxies whose light has been stretched and bent by the large amounts of mass contained in foreground galaxies. This is an effect called "gravitational lensing," predicted by Einstein's Theory of General Relativity that is celebrating its 100th anniversary. X-rays from Chandra show that the two "eye" galaxies and the smaller galaxies associated with them are slamming into one another in a giant galactic collision.