CICLOPS: Cassini Imaging Central Laboratory for OPerationS
Craters 'Twixt Day and Night

Three sizeable impact craters, including one with a marked central peak, lie along the line that divides day and night on the Saturnian moon, Dione (1,123 kilometers, 698 miles across). The low angle of the Sun along the terminator, as this dividing line is called, brings details like these craters into sharp relief.

This view shows principally the leading hemisphere of Dione. Some of this moon's bright, wispy streaks can be seen curling around the moon's eastern limb. Cassini imaged the wispy terrain at high resolution during its first Dione flyby on December 14, 2004.

The image was taken in visible light with Cassini's narrow angle camera on November 1, 2004, from a distance of 2.4 million kilometers (1.5 million miles) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 106 degrees. North is up. The image scale is 14 kilometers (8.7 miles) per pixel. The image has been magnified by a factor of two and contrast enhanced to aid visibility of surface features.

[Caption updated on October 4, 2005.]

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: December 20, 2004 (PIA 06542)
Image/Caption Information
  Craters 'Twixt Day and Night
PIA 06542

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