Andromeda is the nearest spiral galaxy to Earth and is a popular target for astronomers
The Milky Way and its immediate satellites form part of a small galaxy cluster called the Local Group, occupying a volume of space about 10 million light years across. The group contains several dozen galaxies in total, but these are mostly small ‘dwarf spheroidal’ star clouds. Aside from the Milky Way, the other major member is the Andromeda Galaxy – another spiral system that lies about 2.5 million light years away in the constellation of the same name.