ABSTRACT
On late fall or winter nights I like to go out and look for the Andromeda nebula. This fuzzy patch of light among the glittering stars gets its name from its appearance and location: nebula is Latin for cloud, and this small cloud-like object appears in the constellation Andromeda. When the winter night is moonless and there is no haze of light pollution from cities, the Andromeda nebula is so prominent that you don’t need a telescope to see it. It has been known to skywatchers since the tenth century at least, when the Persian astronomer Al-Sufi included it as a ‘‘little cloud’’ in his catalog of the heavens.
