Photograph of the twin galaxies (M81 & M82) in the constellation of Ursa Major (Great Bear) taken on 31 March 1889 with an exposure of 3.5 hours. Dr Isaac Roberts, an amateur astronomer and pioneer astrophotography, took this image using a 20 inch aperture reflecting telescope. Made by Howard Grubb of Dublin, the telescope was first installed at his home near Liverpool, but later in 1890 he moved it to the les smoky skies of Crowborough, Susex. In 1887, Roberts was invited to attend the first international conference in Paris on celestial photography. Here astronomers decided to embark on the, 'Carte du Ciel' an ambitious project to photograph the whole sky in unprecedented detail.
© Science Museum / Science & Society Picture Library