PIA11595: Round the Outside
- Original Caption Released with Image:
The moon Pan casts a shadow on Saturn's outer A ring in this image taken
as the planetapproached its August 2009 equinox.
Pan (28 kilometers, or 17 miles across) orbits in the Encke Gap of the A
ring, and its shadow has been imaged several times by Cassini cast in the
direction of the interior of the A ring (see PIA11652 and PIA11549).
In this image, the shadow is cast in the opposite direction.
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 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
This view looks toward the northern, unilluminated side of the rings from
about 28 degrees above the ringplane.
The image was taken in visible light with the Cassini spacecraft
narrow-angle camera on July 29, 2009. The view was acquired at a distance
of approximately 1.6 million kilometers (994,000 miles) from Pan. Image
scale is 9 kilometers (6 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.
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:
Image and caption provided by the Planetary Photojournal --