A galaxy is a giant group of stars. Our Sun is one of billions of stars in a galaxy called the Milky Way, and the Milky Way is only one of billions of galaxies in the Universe. Galaxies are not usually found on their own; instead they are found in groups called ‘clusters’, and those clusters also form bigger groups called ‘superclusters’.
Galaxies do not look very bright in the night sky. Apart from the Milky Way and two other nearby galaxies called the Magellanic Clouds, only a few can be seen without a telescope. They usually look like faint "fuzzy stars" in the sky.
There are about twenty galaxies in our part of space, which we call the ‘local group’. The biggest one of these is the Andromeda galaxy. It is about twice as big as our own galaxy. This is a picture of Andromeda.
The picture also has two bright patches, one above and one below. These are smaller galaxies.
There are three main types of galaxy. These are called ellipticals, spirals and irregulars.
Click on the links below to find out more about galaxies.
Authors: Carolyn Brinkworth and Claire Thomas
Last updated: July 2001