October 8, 2007
This mosaic of Cassini images shows the smallest details ever observed on Saturn's moon Iapetus.
Visible here are small craters as well as the base of a large mountain ridge located just south of the mosaic. At several places, bright spots about 20 to 50 meters (66 to 164 feet) across are visible. At these locations, more recent impactors have punched through the overlying blanket of dark material to reveal brighter, cleaner ice beneath.
Since the bright craters are relatively small and very shallow, it is likely that the dark blanket is rather thin in this area; it is assumed that its actual average thickness might be on the order of a foot.
The small crater at the upper left edge of the mosaic has a diameter of about 50 meters (164 feet) and shows a distinct ray pattern from excavated ice. This feature is so bright in comparison to the dark surrounding terrain that it had to be darkened manually so as not to look overexposed in this mosaic.
The mosaic consists of eight image footprints across the surface of Iapetus, presented here in simple cylindrical projection. The view is centered on terrain near 0 degrees north latitude, 164.9 degrees west longitude, within the dark leading hemisphere of Iapetus. Image scale is approximately 10 meters (33 feet) per pixel.
The clear spectral filter images in this mosaic were obtained with the Cassini spacecraft narrow-angle camera on Sept. 10, 2007, at distances ranging from 1,627 to 2,040 kilometers (1,011 to 1,268 miles) from Iapetus.
Iapetus is 1,468 kilometers (912 miles) across.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.
Credit: NASA/JPL/Space Science Institute