Shadows of Saturn at Equinox
Unusual shadows and dark rings appeared around Saturn near its equinox last month. At that time -- early August -- Saturn's ring plane pointed directly at the Sun. Visible above , Saturn's moon Tethys casts a shadow visible only on the far right. Saturn's own shadow blacks out a large swath of rings on the right. The night side of Saturn glows with ringshine -- sunlight reflected by ring particles back onto Saturn. Images near equinox at Saturn are giving astronomers a chance to search for unexpected shadows that may illuminate previously unknown features of Saturn's complex ring system . Cassini , the robotic spacecraft orbiting Saturn that took this image , is not expected to survive to the next Saturnian equinox in 15 years.