A Cassini illusion. Click to make the image larger and spot the illusion. Image credit: NASA/JPL/Space Science Institute

Here we have an image of Saturn’s moon Rhea, the F-ring and the little moon directly above Rhea in the rings is Prometheus.

Rhea is the second largest of Saturn’s many moons with a diameter of 949 miles (1,528 km) and Prometheus is only 53 miles (86 km) across.

Having the rings edge-on creates an illusion. Click the image to see the full sized version before clicking the “more” link below to learn what the illusion is.

It appears the moon Rhea is in the foreground.  It’s not.  Rhea is actually further away from Cassini’s camera than the rings and little Prometheus.

To see this image in its original context click here.