In the 1770s, French astronomer Charles Messier was a comet hunter, and in his nightly sweeps of the sky he kept being fooled by fuzzy patches that looked tantalizingly like comets but never moved. Frustrated, he compiled a list of these annoyances — things to ignore. Two and a half centuries later, his comet discoveries are forgotten, and his catalogue of distractions is the most famous deep-sky observing list in history: the Crab Nebula, the Andromeda Galaxy, the Pleiades, the Orion Nebula. Above are the brightest of them, ranked by how high they will climb above Zion tonight.