Peering Through Titan’s Haze
This composite image shows an infrared view of Saturn’s moon Titan from NASA’s Cassini spacecraft, acquired during the mission’s ”T-114” flyby on Nov. 13, 2015.
The spacecraft’s visual and infrared mapping spectrometer (VIMS) instrument made these observations, in which blue represents wavelengths centered at 1.3 microns, green represents 2.0 microns, and red represents 5.0 microns. A view at visible wavelengths (centered around 0.5 microns) would show only Titan’s hazy atmosphere (as in Titan Up Front). The near-infrared wavelengths in this image allow Cassini’s vision to penetrate the haze and reveal the moon’s surface.
During this Titan flyby, the spacecraft’s closest-approach altitude was 6,200 miles (10,000 kilometers), which is considerably higher than those of typical flybys, which are around 750 miles (1,200 kilometers). The high flyby allowed VIMS to gather moderate-resolution views over wide areas (typically at a few kilometers per pixel).
The view looks toward terrain that is mostly on the Saturn-facing hemisphere of Titan. The scene features the parallel, dark, dune-filled regions named Fensal (to the north) and Aztlan (to the south), which form the shape of a sideways letter “H.”
Several places on the image show the surface at higher resolution than elsewhere. These areas, called subframes, show more detail because they were acquired near closest approach. They have finer resolution, but cover smaller areas than data obtained when Cassini was farther away from Titan. Near the limb at left, above center, is the best VIMS view so far of Titan’s largest confirmed impact crater, Menrva (first seen by the RADAR instrument in Circus Maximus). Similarly detailed subframes show eastern Xanadu, the basin Hotei Regio, and channels within bright terrains east of Xanadu. (For Titan maps with named features see http://planetarynames.wr.usgs.gov/Page/TITAN/target.)
Due to the changing Saturnian seasons, in this late northern spring view, the illumination is significantly changed from that seen by VIMS during the “T-9” flyby on Dec. 26, 2005 . The sun has moved higher in the sky in Titan’s northern hemisphere, and lower in the sky in the south, as northern summer approaches. This change in the sun’s angle with respect to Titan’s surface has made high southern latitudes appear darker, while northern latitudes appear brighter.
The Cassini mission is a cooperative project of NASA, ESA (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. 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 http://saturn.jpl.nasa.gov/home/index.cfm. The visual and infrared mapping spectrometer team homepage is at http://www.vims.lpl.arizona.edu.
Credit: NASA/JPL/University of Arizona/University of Idaho
