Hubble's observations depended on improvements in telescope technology, specifically the reflector telescope, which was first developed by Sir Isaac Newton.

While Galileo Galilei is often credited with the first telescopic observations of the cosmos, he used a refractor telescope, which suffers from chromatic aberration (color distortion). Newton's reflector telescope, which uses a mirror to focus light, overcame this problem and proved to be a more powerful tool for astronomical observations.