Atlas joins other moons casting shadows on Saturn's rings as the planet
approaches its August 2009 equinox.
Atlas (30 kilometers, or 19 miles across) orbits in the Roche Division
between the A ring and the thin F ring, and the moon can be see here
casting its shadow on the A ring and across the narrow Keeler Gap. The
novel illumination geometry created as Saturn approaches its August 2009
equinox allows moons orbiting in or near the plane of Saturn's equatorial
rings to cast shadows onto 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. To learn more about this special time and to
see movies of moons' shadows moving across the rings, see PIA11651 and PIA11660.
Stars can be seen through the rings and in the background. They appear
elongated because of the camera's long exposure time.
This view looks toward the unilluminated side of the rings from about 51
degrees above the ringplane. The image was taken in visible light with the
Cassini spacecraft narrow-angle camera on June 28, 2009. The view was
obtained at a distance of approximately 1.5 million kilometers (932,000
miles) from Atlas and at a Sun-Atlas-spacecraft, or phase, angle of 82
degrees. 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.