Three of Saturn's moons have been captured in a single NASA image taken by the Cassini spacecraft. The picture, showing Enceladus, Rhea and Atlas, appears to show only the first two of these moons – but on closer inspection, the latter is hiding on one of Saturn's rings. The image was taken in visible light with Cassini's narrow-angle camera on 24 September last year. It was taken from a distance of around 1.8 million miles from Rhea, 1.3 million miles from Enceladus and 1.5 million miles from Atlas.

"Here, Cassini has captured Enceladus (313 miles or 504 kilometres across) above the rings and Rhea (949 miles or 1,527 kilometres across) below," NASA said in a statement. "The comparatively tiny speck of Atlas (19 miles or 30 kilometres across) can also be seen just above and to the left of Rhea, and just above the thin line of Saturn's F ring."

The Cassini mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. Atlas is one of Saturn's inner moons and was discovered in 1980 from Voyager photos. In total, Saturn has 62 moons, 53 of which have been officially named. Find out more about them here.