Two companion moons share the sky before the Cassini spacecraft. Tethys is seen here with one of its two Trojan moons. Calypso, which trails the larger moon in its orbit by 60 degrees, is a couple of pixels across near lower right. Telesto (not pictured) is the other Tethys co-orbital moon, leading Tethys by 60 degrees.
For higher resolution Cassini views of Calypso (22 kilometers, or 14 miles across) and Tethys (1071 kilometers, or 665 miles across), see Colorful Cratered Calypso and Tethys in Full View, respectively.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Aug. 25, 2007. The view was obtained at a distance of approximately 2.2 million kilometers (1.4 million miles) from Tethys. Image scale is 13 kilometers (8 miles) per pixel on Tethys.
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