An odd red blemish on Saturn's moon Titan has astronomers scratching their heads.

Detected by the Cassini orbiter’s visual and infrared mapping instrument, the red spot may be a hot spot resulting from an impact event or warm material flowing from a cryovolcano, but the definitive cause is unclear, astronomers said. The spot may also be an indicator of a mountain range or terrain covered in some exotic materials, they added.

Cassini took this image on April 16, 2005 during a flyby past Titan. Researchers plan to turn the instrument toward the red spot region during an upcoming July 2, 2006, when Cassini will fly over the area at night. If the red spot is caused by a hot spot, it should glow at night, researchers said.

The red spot is easily picked out at the top of this false-color image of Titan. The anomaly extends across 300 miles (500 kilometers) to the north and west of visibly bright region known to mission scientists as “The Smile” first detected in December 2004. While the two features don’t line up exactly they may be related.

The red spot also sits southeast of Titan’s continent-sized Xanadu region. An overlapping view of Cassini’s visible and infrared views of the region can be seen by clicking the image at left.

In the smaller mosaic at left, astronomers overlaid Cassini’s infrared observations of the red spot (visible in the lower center of the leftmost image) on top of a previous visible light image taken by its imaging science subsystem (center) to build the final composite.

-- SPACE.com Staff

Credit: NASA/JPL/ University of Arizona