Saturn's 'Yin-Yang' moon Iapetus

The US Voyager spacecraft first imaged this curious 'yin-yang' moon in the 1980s, with its light and dark hemispheres. The dark hemisphere is the side of Iapetus that leads in its orbit. In this view, both light and dark areas are visible.

The Cassini-Huygens mission is a co-operative project of NASA, ESA and ASI, the Italian space agency.

Credit: NASA/JPL/Space Science Institute