Astronomy 101: From the Sun and Moon to Wormholes and Warp Drive, Key Theories, Discoveries, and Facts about the Universe (Adams 101 Series)

by Carolyn Collins Petersen

Hubble also discovered that objects in the universe seem to be moving apart, thus showing that the universe is expanding. He determined that the velocity of this so-called “recession” is faster the farther away an object lies from us.