An unparalleled history of astronomy presented in the words of the scientists who made the discoveries. Here are the writings of Copernicus, Galileo, Kepler, Newton, Halley, Hubble, and Einstein, as well as that of dozens of others who have significantly contributed to our picture of the universe. From Aristotle's proof that the Earth is round to the 1998 paper that posited an accelerating universe, this book contains 100 entries spanning the history of astronomy. Award-winning science writer Ma