The Colorful Equator of Rhea
October 7, 2010
These three enhanced-color views of an equatorial region on Saturn’s moon Rhea were made from data obtained by NASA’s Cassini spacecraft. The colors have been enhanced to show colorful splotches and bands on the icy moon’s surface.
Rhea sports a chain of bluish splotches along the equator that appear where fresh, bluish ice has been exposed on older crater rims. Cassini imaging scientists recently reported that they did not see evidence in Cassini images of a ring around Rhea. However, scientists analyzing these enhanced-color views suggest the bluish material could have been exposed by the crash of orbiting material -- perhaps a ring -- to the surface of Rhea in the not too distant past.
These images were made by processing raw images obtained by Cassini's imaging cameras in September 2007. Scientists analyzed frames shot through visible-light, ultraviolet and infrared filters. The processing enhanced our views of these moons beyond what could be seen by the human eye.
The image on the left shows a composite image made from data in the infrared, green and ultraviolet filters. The middle view shows an image made from data analyzing the ratio of infrared to ultraviolet wavelengths, indicating the relative blueness of the features. The image on the right shows a color-coded topography, where purple is 0 elevation and pink is 6 kilometers (4 miles).
In each of these images, the view is centered on 0 degrees north latitude and 163 degrees west longitude. The area shown covers approximately 16,900 square kilometers (6,500 square miles).
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 in Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo.