CICLOPS: Cassini Imaging Central Laboratory for OPerationS
Brotherly Moons

Prometheus and Epimetheus, brothers in Greek mythology, share the stage in this Cassini image of the two moons near the outer A ring and faint F ring.

Prometheus -- meaning `forethought' in Greek -- comes first in this image, tracking ahead in his orbital path. Prometheus (86 kilometers, 53 miles across) is near the right edge, inside the F ring. The moon Epimetheus -- with a name meaning `hindsight' -- comes later, trailing in his orbit. Epimetheus (113 kilometers, 70 miles across) is near the center of the image, outside the F ring.

This view looks toward the sunlit side of the rings from about 64 degrees below the ringplane. The image was taken in visible light with the Cassini spacecraft wide-angle camera on Feb. 15, 2009. The view was obtained at a distance of approximately 971,000 kilometers (604,000 miles) from Epimetheus and at a Sun-Epimetheus-spacecraft, or phase, angle of 109 degrees. Image scale is 58 kilometers (36 miles) per pixel.

The Cassini Equinox Mission is a joint United States and European endeavor. 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 was designed, developed and assembled at JPL. 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 Equinox Mission visit, and

Credit: NASA/JPL/Space Science Institute
Released: March 24, 2009 (PIA 11455)
Image/Caption Information
  Brotherly Moons
PIA 11455

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