The visual and infrared mapping spectrometer instrument onboard Cassini
has found an unusual bright, red spot on Titan.
This dramatic color (but not true color) image was taken during the April
16, 2005, encounter with Titan. North is to the right. In the center it
shows the dark lanes of the "H"-shaped feature (see PIA06407) discovered
from Earth and first seen by Cassini last July shortly after it arrived
in the Saturn system. At the southwestern edge of the "H" feature, near
Titan's limb (edge), is an area roughly 500 kilometers (300 miles) across.
That area is 50 percent brighter, when viewed using light with a
wavelength of 5 microns, than the bright continent-sized area known as
Xanadu (see PIA06107).
Xanadu extends to the northwest of the bright spot, beyond the limb (edge)
of Titan in this image. Near the terminator (the line between day and
night) at the bottom of this image is the 80 kilometer (50 mile) crater
that has been previously seen by the Cassini radar, imaging cameras, and
the visual and infrared spectrometer (see PIA07868).
At wavelengths shorter than 5 microns, the spot is not unusually bright.
The strange spectral character of this enigmatic feature has left the
team with four possibilities for its source: the spot could be a surface
coloration, a mountain range, a cloud, or a hot spot.
The hot spot hypothesis will be tested during a Titan flyby on July 2,
2006, when the visual and infrared spectrometer will take nighttime
images of this area. If it is hot, it will glow at night.
This color image was created from separate images in the 1.7 micron
(blue), 2.0 micron (green), and 5.0 micron (red) spectral windows through
which it is possible to see Titan's surface. The yellow that humans see
has a wavelength of about 0.5 microns, so the colors shown are between 3
and 10 times more red than the human eye can detect.
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 visual and infrared mapping
spectrometer team is based at the University of Arizona.
For more information about the Cassini-Huygens mission visit
http://saturn.jpl.nasa.gov. For additional information on the visual
and infrared mapping spectrometer visit http://wwwvims.lpl.arizona.edu.
