The shadows of Saturn's rings cast onto the planet appear as a thin band at the equator in this image taken as the planet approached its August 2009 equinox.
The novel illumination geometry that accompanies equinox lowers the sun's angle to the ringplane, significantly darkens the rings, and causes out-of-plane structures to look anomalously bright and to cast shadows across the rings. These scenes are possible only during the few months before and after Saturn's equinox which occurs only once in about 15 Earth years. Before and after equinox, Cassini's cameras have spotted not only the predictable shadows of some of Saturn's moons (see PIA11657 ), but also the shadows of newly revealed vertical structures in the rings themselves (see PIA11665 ). For an earlier view of the rings' wide shadows draped high on the northern hemisphere, see PIA09793 .
The planet's southern hemisphere can be seen through the transparent D ring in the lower right of the image. The rings have been brightened by a factor of 9.5 relative to the planet to enhance visibility.
This view looks toward the northern, unilluminated side of the rings from about 30 degrees above the ringplane.
Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were obtained with the Cassini spacecraft wide-angle camera on July 18, 2009 at a distance of approximately 2.1 million kilometers (1.3 million miles) from Saturn. Image scale is 122 kilometers (76 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.
|Target||Saturn Rings||D Ring, Earth, Saturn, Sun|
|Target Type||Ring||Earth, Planet, Sun|
|Instrument Host||Cassini Orbiter|
|Instrument||Imaging Science Subsystem (ISS)|
|Detector||Wide Angle Camera|
|Extra Keywords||Color, Shadow|
|Date in Caption||2009-07-18|
|Image Credit||NASA/JPL/Space Science Institute|