Explanation: How far can you see? The Andromeda Galaxy 2.5 million light years away is the most distant object easily seen by the unaided eye. Other apparent denizens of the night sky, stars, clusters, and nebulae, typically range from a few hundred to a few thousand light-years away and lie well within our own Milky Way Galaxy. Also known as M31, the Andromeda Galaxy is the faint smudge near top center of this Earth and skyscape, taken from eastern Italy, near Monte Conero on the Adriatic sea coast. From a few centimeters to a few million light-years, the picture demonstrates...