CICLOPS: Cassini Imaging Central Laboratory for OPerationS
Details in the Dark

This view shows one of Iapetus' huge impact basins on the terminator and a smaller, but still fairly large, crater near the southern bright-dark boundary. Just visible near the western limb, in the dark territory of Cassini Regio, is the moon's mysterious equatorial ridge. The ridge was discovered in Cassini images (see PIA06166) and reaches 20 kilometers (12 miles) high in places.

This view shows principally the leading hemisphere on Iapetus. North is up and tilted 15 degrees to the right. Iapetus is 1,471 kilometers (914 miles) across.

The image was taken with the narrow angle camera on March 19, 2005, through spectral filters sensitive to wavelengths of infrared light centered at 752 nanometers. The view was acquired from a distance of approximately 1.4 million kilometers (880,000 miles) from Iapetus and at a Sun-Iapetus-spacecraft, or phase, angle of 70 degrees. Resolution in the original image was 8 kilometers (5 miles) per pixel.

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 Cassini-Huygens mission for NASA's Science Mission Directorate, Washington, D.C. The imaging team consists of scientists from the US, England, France, and Germany. The imaging operations center and team lead (Dr. C. Porco) are based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini-Huygens mission, visit and the Cassini imaging team home page,

Credit: NASA/JPL/Space Science Institute
Released: May 11, 2005 (PIA 06646)
Image/Caption Information
  Details in the Dark
PIA 06646

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