Crescent Japetus

Caption NASA:"Japetus shows off its puzzling light and Dark Terrain.
Scientists continue to investigate the nature of this moon's Surface. Lit Terrain seen here is on the Saturn-facing side of Japetus. North on Japetus is up and rotated 8° to the left. Scale in the original image was approx. 7 Km (about 4,5 miles) per pixel. The image has been magnified by a factor of 2 and contrast-enhanced to aid visibility.

The image was taken in Visible Light with the Cassini Spacecraft narrow-angle camera on Sept. 13, 2009. The view was obtained at a distance of approx. 1,2 MKM (such as about 746.000 miles) from Japetus and at a Sun-Japetus-Spacecraft, or Phase, Angle of 103°".