CICLOPS: Cassini Imaging Central Laboratory for OPerationS
Contemplative Janus

Janus (111 miles or 179 kilometers across) seems to almost stare off into the distance, contemplating deep, moonish thoughts as the F ring stands by at the bottom of this image.

From this image, it is easy to distinguish Janus' shape from that of a sphere. Many of Saturn's smaller moons have similarly irregular shapes that scientists believe may give clues to their origins and internal structure. Models combining the dynamics of this moon with its shape imply the existence of mass inhomogeneities within Janus. This would be a surprising result for a body the size of Janus. By studying more images of Janus, scientists may be able confirm this finding and determine just how complicated the internal structure of this small body is.

This image is roughly centered on the side of Janus which faces away from Saturn. North on Janus is up and rotated 3 degrees to the right. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on March 28, 2012.

The view was obtained at a distance of approximately 54,000 miles (87,000 kilometers) from Janus. Image scale is 1,700 feet (520 meters) per pixel.

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/Space Science Institute
Released: January 19, 2015 (PIA 18299)
Image/Caption Information
  Contemplative Janus
PIA 18299

Avg Rating: 9.82/10

Full Size 1020x1020:
PNG 200 KB

Alliance Member Comments
Tim01 (Feb 16, 2015 at 5:32 AM):
It's really awesome feat of NASA