Lord of the Rings
Saturn casts a long shadow across its icy rings in a 2007 picture taken by NASA's Cassini-Huygens spacecraft—an unattainable perspective from Earth's line of sight. The picture is among Cassini's ten best, chosen by National Geographic News photo editors to mark the probe's anniversary.
Fifteen years ago this week, a Titan rocket launched the bus-size spacecraft from Cape Canaveral, Florida. In July 2004 Cassini finally entered Saturn orbit. Since then the probe has beamed back a steady stream of some 300,000 pictures and nearly 450 gigabytes of data about the ringed giant and its dozens of enigmatic moons.
Scientists used red, green, and blue filters to create the above natural-color mosaic, taken 700,000 miles (over a million kilometers) above Saturn's northern hemisphere.
After completing its extended mission in 2017, Cassini will likely be commanded to plunge into the gas-giant planet to prevent contamination of its moons, including Titan and Enceladus. (See "Pictures: Saturn Moon Coated in Fresh Powder.")