http://www.theregister.co.uk/2007/08/24/uranus_rings/
The picture is extremely rare because the rings happen to be tilted perfectly edge on to Earth, an alignment that happens just twice every 894 years as the planet orbits the sun.
The planet is a bit of an oddball because it is orbiting the Sun on its side, with its axis almost parallel to the path it takes around our star.
Learn something new every day.