Caption

Andromeda Galaxy. 19th-century astronomical observation of the Andromeda Galaxy (M31, NGC 224). North is at left. At the time, such objects were still thought to be nebulae, and this one was known as the Great Andromeda Nebula. M31, the largest of the Local Group of galaxies, is around 2.5 million light years away, in the constellation of Andromeda. This 120-minute exposure was obtained on 1 October 1888, from the observatory in Maghull, Merseyside, UK. This observatory was operated by British amateur astronomer Isaac Roberts (1829-1904), one of the pioneers of the new techniques of astrophotography.