The glow of Titan's extensive atmosphere shines in false colors in this
view of Saturn's gas-enshrouded moon acquired by the Cassini spacecraft
visual and infrared mapping spectrometer during the July 2, 2004, flyby.
This image is a combination of near-infrared colors, each of which probes
different phenomena in the moon.
From its vantage point over Titan's terminator, both the dayside and
nightside of the crescent moon are seen, with the sunlit side on the left.
In this false color rendition, green light is the fluorescent emission of
methane gas powered by sunlight, at a wavelength of 3.3 microns. This is
some five times the wavelength visible to the human eye. The glow extends
over 700 kilometers (435 miles) above the surface, revealing the unusual
thickness of the moon's atmosphere, which nearly doubles Titan's volume
compared to the volume of the solid sphere, indicated by the solid line.
On the nightside (right side), the moon glows red out for over 200
kilometers (125 miles) altitude, indicating carbon-monoxide emission at
4.7 micron wavelength produced in Titan's relatively warm stratosphere.
This glow actually extends over the dayside as well, producing the yellow
layer observed on the left as the two glows from methane (green) and
carbon monoxide (red) mix together in this rendition. Titan's surface is
indicated by the circle determined by a surface image at 2.0 microns
blue), which is unaffected by atmospheric glows showing the sunlit
surface. Here, due to the reddish glow of carbon monoxide overlying the
blue-colored surface, most of the dayside appears purplish in color.
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 was designed, developed
and assembled at JPL. The visible and infrared mapping spectrometer team
is based at the University of Arizona, Tucson.
For more information about the Cassini-Huygens mission visit,
http://saturn.jpl.nasa.gov. For more information about the visual
and infrared mapping spectrometer visit http://wwwvims.lpl.arizona.edu/.
