NASA's Cassini spacecraft snapped this image of Saturn's icy moon Iapetus on Dec. 31, 2004 at a range of about 44,725 miles (71,978 kilometers).

Iapetus (pronounced eye-APP-eh-tuss) has a diameter about one third that of our own Moon at 892 miles (1,436 kilometers).

Iapetus was discovered by the Italian-French astronomer Jean Dominique Cassini in 1672. He correctly deduced that the trailing hemisphere is composed of highly reflective material, while the leading hemisphere is strikingly darker.

Imaging coverage of Iapetus by Cassini was focused primarily on the dark terrain of Iapetus' leading hemisphere, in the area known as Cassini Regio.

Images from this Cassini flyby are superior in resolution to those obtained by Voyager 2 in August 1981, officials said.

-- SPACE.com Staff

Credit: NASA/JPL/ Space Science Institute