Cassini Image: Saturn Through The Blue Filter

http://saturn.jpl.nasa.gov/cgibin/gs...jpg&type=image

Blue Saturn
March 19, 2004
Full-Res: PIA05383 -
http://photojournal.jpl.nasa.gov/catalog/PIA05383

Bands and spots in Saturn's atmosphere, including a dark band south
of the equator with a scalloped border, are visible in this image from
the Cassini-Huygens spacecraft.

The narrow-angle camera took the image in blue light on Feb. 29, 2004.
The distance to Saturn was 59.9 million kilometers (37.2 million
miles).
The image scale is 359 kilometers (223 miles) per pixel.

Three of Saturn's moons are seen in the image: Enceladus (499
kilometers,
or 310 miles across) at left; Mimas (398 kilometers, or 247 miles
across)
left of Saturn's south pole; and Rhea (1,528 kilometers, or 949 miles
across)
at lower right. The imaging team enhanced the brightness of the moons
to
aid visibility.

The BL1 broadband spectral filter (centered at 451 nanometers) allows
Cassini to "see" light in a part of the spectrum visible as the color
blue to human eyes. Scientist can combine images made with this filter
with those taken with red and green filters to create full-color
composites.

In this image, everything on the planet is a cloud, and the contrast
between bright and dark features is determined by the different
blue-light
absorbing properties of the particles that comprise the clouds. White
regions contain material reflecting in the blue; dark regions contain
material absorbing in the blue. This reflecting/absorbing behavior is
controlled by the composition of the cloud's colored material, which
is
still a mystery -- one which may be answered by Cassini. The differing
concentrations of this material across the planet are responsible for
its banded appearance in the visible region of the electromagnetic
spectrum.

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 Office of
Space Science, Washington, D.C. 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 .

Image Credit:
NASA/JPL/Space Science Institute