Andromeda is one of the very few galaxies you can see with your naked eye from a dark site. It’s easy in binoculars, and if you use a small telescope, the galaxy fills the eyepiece.
However, that’s just the core, the nucleus, of Andromeda. Like the Milky Way, Andromeda has vast spiral arms that extend well out from the core. From Earth, the galaxy appears to be more than 3 degrees across — remember, there are 90 degrees in a right angle, and 360 degrees in a circle; astronomers use angular size as a way to measure how big an object is on the sky.The Moon is about 0.5 degrees across (about half the width of your thumb held at arm’s length), so Andromeda is about six times bigger. Edited from Slate