It looks like two Saturnian satellites in this Cassini image, but there are actually three. Can you spot the third one? It took me a few minutes (and the assistance of my eyeglasses) to find it. But don’t worry, I’ve got the clues right here for you.
Enceladus (313 miles or 504 kilometers across) is floating above Saturn’s rings, while Rhea (949 miles or 1,527 kilometers across) appears below the ring plane.
The third and almost invisible satellite Atlas (19 miles or 30 kilometers across) can also be seen just above and to the left of Rhea, and just above the thin line of Saturn’s F ring.
This view was obtained by Cassini from a distance of approximately 1.8 million miles (2.8 million kilometers) from Rhea. Image scale on Rhea is 10 miles (16 kilometers) per pixel. The distance to Enceladus was 1.3 million miles (2.1 million kilometers) for a scale of 5 miles (8 kilometers) per pixel. The distance to Atlas was 1.5 million miles (2.4 million) kilometers) for an image scale at Atlas of 9 miles (14 kilometers) per pixel.
Full size image is available on the NASA website.