During a recent pass of Titan (5,150 kilometers, 3,200 miles across), one of more than 40 during Cassini’s nominal 4-year mission, the spacecraft acquired this infrared view of the bright Xanadu region and the moon’s south pole.
Southeast of Xanadu (and above center in this view) is the peculiar semi-circular feature informally referred to by imaging scientists as “the Smile.” This surface feature is the brightest spot on Titan's surface, not only to the Imaging Science Subsystem cameras, but also to the VIMS instrument, which sees the surface at even longer wavelengths (see PIA 07876). The Smile is 560 kilometers (345 miles) wide.
At the landing site of the successful Huygens probe mission, brighter regions correspond to icy upland areas, while the darker regions are lowlands which possess a higher proportion of the organic byproducts of Titan's atmospheric photochemistry. Those results seem to confirm the long-standing hypothesis that Xanadu is a relatively high region of less contaminated ice. However, the cause of the even brighter "Smile" is a mystery that is still under study.
Farther south, a field of bright clouds arcs around the pole, moving at a few meters per second. Around the limb, Cassini peers through Titan’s smoggy, nitrogen-rich atmosphere.
North in this image is toward the upper left.
The image was taken with the narrow angle camera on June 4, 2005, from a distance of approximately 1.2 million kilometers (700,000 miles) from Titan using a spectral filter sensitive to wavelengths of infrared light centered at 938 nanometers. The image scale is 7 kilometers (4 miles) per pixel.
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 imaging team consists of scientists from the US, England, France, and Germany. The imaging operations center and team lead (Dr. C. Porco) are based at the Space Science Institute in Boulder, Colo.