Cassini’s third close approach to Titan on Tuesday, February 15 yielded
intriguing new views of the planet-sized moon, as the spacecraft’s
powerful cameras looked at and through the orange murk of its thick
atmosphere. Cassini sped past Titan, coming within 1,580
kilometers (982 miles) of the moon’s surface. This was the spacecraft’s
first pass by Titan since the European Space Agency’s
Huygens probe parachuted to a successful landing on Jan. 14.
Images taken during the flyby, processed to enhance surface visibility and
composed into a mosaic, show surface details that include improved looks
at previously seen territory to the north and west
of the large, bright region called Xanadu. Some of this territory has also been
observed by other Cassini instruments (RADAR and VIMS) during this flyby.
Scientists will be comparing their results
from these different instruments in forthcoming days to get a more complete
picture of the Titan surface.
Tne new image taken just prior to the flyby shows that some of the moon’s
surface and atmospheric features can readily be seen using Cassini’s clear
spectral filter, which is sensitive to a broad range of light, from
ultraviolet to near-infrared. Imaging scientists normally
use a narrow-band infrared filter centered at 938 nanometers, where atmospheric
methane is less absorbing, to look at Titan’s surface and cloud features.
Images taken in the clear filter between Titan flybys are used
primarily to navigate the spacecraft.
Although the clear filter is not the best way to view the surface, this
finding demonstrates that with sufficient processing this filter can be
used to track cloud features in inter-flyby periods and thus provide a
better understanding of the evolution of Titan’s atmosphere as spring
approaches in the northern hemisphere.
Another of the images released today, taken after closest approach of
Titan’s night side, shows the thick atmosphere illuminated from behind by
sunlight. In this image, a thin, detached haze layer is visible over the
entire globe. The haze layer over the north polar region (at top) has a
different structure, a feature that imaging scientists have noticed in
earlier flybys. The outermost haze layer is very circular around the whole
disk, but the structure beneath this circle is different near the
north pole.
Finally, a natural color view, showing the moon’s globe-enshrouding orange
haze, also is included in today’s image products.
The pictures are available at http://ciclops.org, http://saturn.jpl.nasa.gov
and
http://www.nasa.gov/cassini.
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 European Space
Agency built and managed the development of the Huygens probe and is in
charge of the probe operations. The Italian Space Agency provided the
high-gain antenna, much of the radio system and elements of several of
Cassini’s science instruments. The imaging team is based at the Space
Science Institute, Boulder, Colo.
