Rings of Planet Saturn (April 28 - 30, 2013) -- Space Weather posting

www.spaceweather.com/

SATURN'S RINGS SURGE IN BRIGHTNESS: This week Saturn is at opposition--that is, opposite the sun in the skies of Earth. Saturn rises at sunset and soars almost overhead at midnight, up all night. This arrangement has a striking effect on Saturn's rings. It makes them bright. Amateur astronomer Christopher Go of the Philippines photographed the phenomenon on April 28th:

"The rings are very bright due to the Seeliger Effect," says Go. Also known as the "opposition effect," the Seeliger effect has been observed on the Moon, Earth and Mars. It happens when sunlit objects (such as the icy particles that make up Saturn's rings) hide their own shadows. A process called coherent backscattering may also contribute to the extra luminosity.
Whatever the details may be, the net result is beautiful. The Seeliger Effect should be operative for a few more days. Readers with backyard telescopes should take a look.