Galaxies in the River . ... Image data: ESO /Danish 1.5m telescope at La Silla , Chile - 2008 Explanation: Large galaxies grow by eating small ones. ... Located over 50 million light years away, the large, distorted spiral NGC 1532 is seen locked in a gravitational struggle with dwarf galaxy NGC 1531, a struggle the smaller galaxy will eventually lose . ... The NGC 1532/1531 pair is thought to be similar to the system of face-on spiral and small companion known as M51, the Whirlpool Galaxy . ...