This image shows two moons of Saturn, Mimas on the right and Dione on the left. And though you might find it hard to believe, that dark line running through the centre is in fact Saturn's ring.
The image was captured looking towards Saturn at a distance of one million kilometres but from less than one degree above the plane of the ring. The side of the ring appears entirely unilluminated, while the moons, bathed in light, almost appear to be gazing up at the giant planet behind. You may hope a larger picture such as the one below would help provide a sense of scale -- but actually Saturn is so vast that it doesn't really help much.