Saturn's moon Dione passes in front of the larger moon Titan, as seen from the Cassini spacecraft.
This image is part of a mutual event sequence in which one moon passes close to or in front of another. Such observations help scientists refine their understanding of the orbits of Saturn's moons. See Catching Big Sister to watch a movie of a mutual event.
Lit terrain seen here is on the anti-Saturn side of Dione (1,123 kilometers, or 698 miles across) and the leading hemisphere of Titan (5,150 kilometers, or 3,200 miles across).
The image was taken in visible blue light with the Cassini spacecraft narrow-angle camera on March 12, 2010. The view was obtained at a distance of approximately 2.2 million kilometers (1.4 million miles) from Dione and 3.6 million kilometers (2.2 million miles) from Titan. Scale in the original image was 13 kilometers (8 miles) per pixel on Dione and on 21 kilometers (13 miles) per pixel Titan. The image has been magnified by a factor of 1.5 and contrast-enhanced to aid visibility.
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