Icy sentinels stand guard on Saturn's doorstep, defying the distant Sun.
Tethys (1,071 kilometers, or 665 miles across) is seen here at left, along with Enceladus (505 kilometers, 314 miles across), against the planet. At the distance of Saturn, the Sun's light is only about one-hundredth of its intensity at Earth, making this a dim and cold domain.
This view looks toward the sunlit side of the rings from about 5 degrees below the ringplane.
The image was taken with the Cassini spacecraft wide-angle camera on Sept. 20, 2007 using a spectral filter sensitive to wavelengths of infrared light centered at 752 nanometers. The view was acquired at a distance of approximately 3.3 million kilometers (2 million miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 52 degrees. Image scale is 193 kilometers (120 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