Saturn hosts its own miniature solar system, with an entourage of more
than 30 moons. This image shows Saturn's A and F rings, along with three
of the moons that orbit close to them.
From innermost to outermost, tiny Atlas (32 kilometers, or 20 miles,
across) orbits just outside of the bright A ring and is seen above center
in this view. Prometheus (102 kilometers, or 63 miles, across) is visible
near lower right. Prometheus and its smaller cohort, Pandora, shepherd
the thin, knotted F ring. Finally Janus (181 kilometers, or 112 miles,
across) can be seen near lower left. Janus shares its orbit with the moon
Epimetheus.
Density waves due to Janus cause some of the bright bands seen in the A
ring in this image. Prometheus and Atlas also produce waves in the rings,
but their wave regions are too narrow to be seen here. The interactions
of the moons with each other and the rings are a major target of study for
the Cassini mission.
The planet's shadow stretches all the way across the main rings in this
view. The shadow has an oval shape at present, but over the next few years
will become more rectangular as the planet orbits the Sun and the angle
at which sunlight strikes the rings decreases. For an example of this from
NASA's Voyager mission, see http://photojournal.jpl.nasa.gov/catalog/PIA00335.
The image was taken with the Cassini spacecraft narrow angle camera on
Oct. 6, 2004, at a distance of 6.4 million kilometers (4 million miles)
from Saturn through a filter sensitive to wavelengths of visible red
light. The image scale is 38 kilometers (24 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 Cassini-Huygens 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 team
is based at the Space Science Institute, Boulder, Colo.
For more information, about the Cassini-Huygens mission visit,
http://saturn.jpl.nasa.gov and the Cassini imaging team home page,
http://ciclops.org.
