One of nineteen photographs from the Royal Observatory, Cape of Good Hope, South Africa, showing a view of the emission nebula, Eta Carina. A 24 hour exposure taken with the Astrographic Telescope by Howard Grubb made for the 'Carte du Ciel' photographic sky survey.

Photograph showing the emission nebula, Eta Carina (formerly Eta Argus) taken using the astrographic telescope at the Cape Observatory in South Africa. Located at the centre of this intricate nebula is a massive but unstable star that one day will explode spectacularly. Made around 1909 and exposed for 24 hours, the image is one of a series taken as part of the Carte du Ciel, project to map the heavens in unprecedented detail. Started in1887, the mammoth undertaking was not completed until the middle years of the 20th century. Today it forms a valuable resource for comparison with present-day high precision surveys of the position of stars using spacecraft.