This eBook describes the rise of telescopic astronomy in Western Europe, the early 17th century, and the emergence of the Scientific Revolution. Readers will explore the work of American astronomer Edwin Powell Hubble who showed that the universe was not static, but rather expanding. As demonstrated by the special collection of NASA’s Hubble Space Telescope images presented in Optical Astronomy, Hubble’s over 1.4 million images have transformed how scientists observe the universe and some of its most mysterious phenomena. This eBook is a must-read for any student interested in how astronomers use telescopes to study planets, stars, galaxies, and the structure of the universe.