Prometheus and Epimetheus, brothers in Greek mythology, share the stage in this Cassini spacecraft 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 its orbital path. Prometheus (86 kilometers, or 53 miles across) is near the right edge, inside the F ring. The moon Epimetheus -- with a name meaning `hindsight' -- comes later, trailing in its orbit. Epimetheus (113 kilometers, or 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 (603,000 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-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