PIA07761: Cosmic Blasting Zone
Target Name: Hyperion
Is a satellite of: Saturn
Mission: Cassini-Huygens
Spacecraft: Cassini Orbiter
Instrument: Imaging Science Subsystem - Narrow Angle
Product Size: 1800 x 2115 pixels (width x height)
Produced By: Cassini Imaging Team
Primary Data Set: Cassini
Full-Res TIFF: PIA07761.tif (3.811 MB)
Full-Res JPEG: PIA07761.jpg (265.8 kB)

Click on the image above to download a moderately sized image in JPEG format (possibly reduced in size from original)

Updated Caption: (View Original Caption)

Saturn's impact-pummeled Hyperion stares back at Cassini in this six-image mosaic taken during the spacecraftís close approach on Sept. 26, 2005.

This up-close view shows a low density body blasted by impacts over the eons. Scientists originally believed that the spongy appearance of Hyperion is caused by a phenomenon called thermal erosion, in which dark materials accumulating on crater floors are warmed by sunlight and melt deeper into the surface, allowing surrounding ice to vaporize away.

Cassini scientists now think that Hyperionís unusual appearance can be attributed to the fact that it has an unusually low density for such a large object, giving it weak surface gravity and high porosity. These characteristics help preserve the original shapes of Hyperionís craters by limiting the amount of impact ejecta coating the moonís surface. Impactors tend to make craters by compressing the surface material, rather than blasting it out. Further, Hyperionís weak gravity, and correspondingly low escape velocity, means that what little ejecta is produced has a good chance of escaping the moon altogether.

At 280 kilometers, (174 miles) across, Hyperionís impact-shaped morphology makes it the largest of Saturn's irregularly-shaped moons.

Six, clear-filter images were combined to create this mosaic. Images were taken by the Cassini spacecraft narrow-angle camera at a mean distance of about 33,000 kilometers (20,500 miles) from Hyperion and at a sun-Hyperion-spacecraft, or phase, angle of 51 degrees. Image scale is 197 meters 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.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov. The Cassini imaging team homepage is at http://ciclops.org.

Image Credit:
NASA/JPL/Space Science Institute

Image Addition Date:
2005-12-06