CICLOPS: Cassini Imaging Central Laboratory for OPerationS

Pan Revealed
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These two images from NASA's Cassini spacecraft show how the spacecraft's perspective changed as it passed within 15,300 miles (24,600 kilometers) of Saturn's moon Pan on March 7, 2017. This was Cassini's closest-ever encounter with Pan, improving the level of detail seen on the little moon by a factor of eight over previous observations.

The views show the northern and southern hemispheres of Pan, at left and right, respectively. Both views look toward Pan's trailing side, which is the side opposite the moon's direction of motion as it orbits Saturn.

Cassini imaging scientists think that Pan formed within Saturn's rings, with ring material accreting onto it and forming the rounded shape of its central mass, when the outer part of the ring system was quite young and the ring system was vertically thicker. Thus, Pan probably has a core of icy material that is denser than the softer mantle around it.

The distinctive, thin ridge around Pan's equator is thought to have come after the moon formed and had cleared the gap in the rings in which it resides today. At that point the ring was as thin as it is today, yet there was still ring material accreting onto Pan. However, at the tail end of the process, that material was raining down on the moon solely in (or close to) its equatorial region. Thus, the infalling material formed a tall, narrow ridge of material. On a larger, more massive body, this ridge would not be so tall (relative to the body) because gravity would cause it to flatten out. But Pan's gravity is so feeble that the ring material simply settles onto Pan and builds up. Other dynamical forces keep the ridge from growing indefinitely.

These views are also presented in stereo (3-D) in PIA21435. The images are presented here at their original size.

The views were acquired by the Cassini narrow-angle camera at distances of 15,275 miles or 24,583 kilometers (left view) and 23,199 miles or 37,335 kilometers (right view). Image scale is 482 feet or 147 meters per pixel (left view) and about 735 feet or 224 meters per pixel (right view).

See PIA09868 and PIA11529 for more distant context views of Pan.

The Cassini Solstice Mission is a joint United States and European endeavor. 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 was designed, developed and assembled at JPL. The imaging team consists of scientists from the US, England, France, and Germany. The imaging operations center and team lead (Dr. C. Porco) are based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini Solstice Mission visit, and

Credit: NASA/JPL-Caltech/SSI
Released: March 16, 2017 (PIA 21436)
Image/Caption Information
  Pan Revealed
PIA 21436

Avg Rating: 9.82/10

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Alliance Member Comments
Dragon_of_Luck_Mah_Jonng1971 (Apr 5, 2017 at 5:59 PM):
It's looking completely different from what I expected.
Even more surprising its ridge looks smoother than the rest of its surface although it looks like being connected all the way round to its main body.

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