Incredible composite image shows nearly a million of Hubble's observations in a single photo

It's estimated that the Hubble Space Telescope has performed about 1.4 million observations since launching into space in 1990. Those are a lot of opportunities to look at different parts of the sky. As Dr. Casey Handmer points out, given Hubble's 202 arc-second field of view, about 3.5 million exposures would cover the entire sky. Dr. Handmer then wondered, how much of the sky has Hubble seen? In the pursuit of answering this question, Dr. Handmer, who earned a Ph.D. in the Theoretical AstroPhy...