Japet, satellite of Saturn, seen by Cassini - Saturn's moon Iapetus seen by Cassini spacecraft...

Japet, satellite of Saturn, seen by Cassini - Saturn's moon Iapetus seen by Cassini spacecraft - Comparison of the two hemispheres of Japet, a satellite of Saturn of 1471 kilometres in diameter. Its main feature is the color difference between the two hemispheres. On the left, the dark region called Cassini Regio with to the east the largest crater of Japet, named Turgis (580 km in diameter). On the right, the bright side of the satellite with Roncevaux Terra (north) and Saragossa Terra (south) housing the large impact crater Engelier (504 km in diameter). Both images were obtained by the Cassini probe on 10 September 2007 (right) and 27 December 2004 (left). These two global images of Iapetus show the extreme brightness dichotomy on the surface of this peculiar Saturnian moon. The left - hand panel shows the moon's leading hemisphere and the right - hand panel shows the moon's trailing side. While low and mid latitudes of the leading side exhibit a surface almost as dark as charcoal, broad tracts of the trailing side are almost as bright as snow. The dark terrain covers about 40 percent of the surface and is named Cassini Regio. The names of the bright terrain are Roncesvaux Terra (north) and Saragossa Terra (south). On both hemispheres, the dominant landforms are impact craters. The largest known well - preserved basin on Iapetus, called Turgis, has a diameter of about 580 kilometers (360 miles). It lies at 17 degrees north latitude, 28 degrees west longitude at the eastern edge of the dark Cassini Regio and is visible on the right side of the left - hand panel. The prominent basin on the southern trailing side (at the lower left of the right - hand panel) is Engelier. Engelier is located at 41 degrees south latitude, 265 degrees west longitude, and has a diameter of about 504 kilometers (313 miles). Its formation destroyed about half of Gerin, another large basin on Iapetus. Gerin is located at 46 degrees south latitude, 233 degrees