Click on the image for movie of
Movie of Saturn's "Ring Current"
This movie is made up of over 600 consecutive images taken on March 16 to
March 18, 2007, with the Cassini Magnetospheric Imaging Instrument's ion
and neutral camera.
The movie clip shows Saturn's dynamic "ring current," which is an
invisible ring of energetic ions trapped in the magnetic field of the
The ion and neutral camera allows scientists to produce movies that show
how this ring changes over time and these movies reveal a dynamic system.
The ring current is doughnut shaped but in some instances it appears like
someone took a bite out of it. (For a related image see PIA10082).
The ion and neutral camera records the intensity of the escaping
particles, which provides a map of the ring current. In this movie, the
colors represent the intensity of the neutral emission, which is a
reflection of the trapped ions. This "ring" is much farther from Saturn
(roughly five times farther) than Saturn's famous icy rings. Red
represents the higher intensity of the particles, while blue is less
Saturn's ring current had not been mapped before on a global scale, only
"snippets" or areas were mapped previously but not in this detail.
The spacecraft coordinates are shown with each frame. Saturn is at the
center and the dotted circles represent the orbits of the moon's Rhea and
Titan. The Z axis points parallel with Saturn's spin axis, the X-axis
points roughly sunward in the sun-spin axis plane, and Y completes the
system, roughly toward dusk. The magenta-colored axes represent a
longitude system rotating with the planet, developed by the radio and
plasma wave instrument team.
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 was designed, developed and assembled at JPL. The
magnetospheric imaging instrument was designed, built and is operated by
an international team lead by the Applied Physics Laboratory of the Johns
Hopkins University, Laurel, Md.
For more information about the Cassini-Huygens mission, visit
http://saturn.jpl.nasa.gov/home/index.cfm and the instrument
team's home page, http://sd-www.jhuapl.edu/CASSINI/index.html.