Aug 9, 2011 07:18 GMT  ·  By

After several weeks of relative inactivity, the NASA Cassini orbiter managed to snap a new set of pictures covering a large portion of Titan, Saturn's largest moon. The image reveals a large number of dunes and craters, as well as the enigmatic bright feature called Xanadu.

The latter is located on the leading edge of the moon. Experts have no way of explaining how this highly-reflective region developed in the first place. Astronomers first detected it using the Hubble Space Telescope, back in 1994.

Interestingly, Xanadu is very large, about the size of Australia, experts at the NASA Jet Propulsion Laboratory (JPL), in Pasadena, California, explain. The area exhibits a very high level of contrast when compared to surrounding regions, which are quite dark..

On Titan, extremely cold temperatures are causing hydrocarbons such as methane and ethane to unfreeze, and become liquid. Lakes at both the north and south poles are made up of these chemicals, as are the rains that fall from the moon's atmosphere.

Despite all this, the Xanadu feature appears to be made up of water ice, which is the only possibility experts could think of to explain what the plateau-like formation is. During the latest observations session, Cassini captured an interesting array of features that adorn Titan's surface.

In order to pierce the moon's thick, hazy atmosphere, the NASA orbiter used the Titan Radar Mapper to image this region of the celestial object on June 21, 2011. The crater Ksa – in the upper right part of the image – was also imaged again. Cassini discovered this feature about 5 years ago.

“The dune fields on Titan, Saturn's largest moon, nearly girdle the globe at latitudes from about 30 degrees north to 30 degrees south, with the notable exception of Xanadu. In this image, the dunes overlap Xanadu only slightly,” Cassini's science team reveals.

“They are also more widely separated and discontinuous at the boundary, a characteristic typical of dunes on Earth where the sand supply is limited. The dunes also either wind their way around or terminate at other, smaller features, including Ksa,” they add.

The Titan Radar Mapper instrument is in fact a synthetic-aperture radar (SAR) that can easily penetrate the atmosphere. Similar devices are also outfitted on Earth-observation satellites, and are used to study a variety of features over difficult, cloudy areas such as Antarctica.

According to experts at JPL, the new image of Titan covers an area 350 kilometers (217 miles) high by 930 kilometers (578 miles) wide, and features a resolution level of 350 meters per pixel.