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takyon writes:

http://www.jpl.nasa.gov/news/news.php?feature=6614

New scenes from a frigid alien landscape are coming to light in recent radar images of Saturn's largest moon, Titan, from NASA's Cassini spacecraft. Cassini obtained the views during a close flyby of Titan on July 25, when the spacecraft came as close as 607 miles (976 kilometers) from the giant moon. The spacecraft's radar instrument is able to penetrate the dense, global haze that surrounds Titan, to reveal fine details on the surface. One of the new views shows long, linear dunes, thought to be comprised of grains derived from hydrocarbons that have settled out of Titan's atmosphere. Cassini has shown that dunes of this sort encircle most of Titan's equator. Scientists can use the dunes to learn about winds, the sands they're composed of, and highs and lows in the landscape.

[...] Another new image shows an area nicknamed the "Xanadu annex" earlier in the mission by members of the Cassini radar team. Cassini's radar had not previously obtained images of this area, but earlier measurements by the spacecraft suggested the terrain might be quite similar to the large region on Titan named Xanadu. First imaged in 1994 by NASA's Hubble Space Telescope, Xanadu was the first surface feature to be recognized on Titan. While Hubble was able to see Xanadu's outline, the annex area went unnoticed. The new Cassini image reveals that the Xanadu annex is, indeed, made up of the same type of mountainous terrains observed in Xanadu and scattered across other parts of Titan.

[...] The July 25 flyby was Cassini's 122nd encounter with Titan since the spacecraft's arrival in the Saturn system in mid-2004. It was also the last time Cassini's radar will image terrain in the far southern latitudes of Titan. [...] Cassini's four remaining Titan flybys will focus primarily on the liquid-filled lakes and seas in Titan's far north. The mission will begin its finale in April 2017, with a series of 22 orbits that plunge between the planet and its icy rings.

Wikipedia has a summary which notes many interesting properties of Titan:

[Continues...]

​​​​​Titan (or Saturn VI) is the largest moon of Saturn. It is the only natural satellite known to have a dense atmosphere, and the only object other than Earth where clear evidence of stable bodies of surface liquid has been found.

Titan is the sixth ellipsoidal moon from Saturn. Frequently described as a planet-like moon, Titan's diameter is 50% larger than Earth's natural satellite, the Moon, and it is 80% more massive. It is the second-largest moon in the Solar System, after Jupiter's moon Ganymede, and is larger than the smallest planet, Mercury, although only 40% as massive. Discovered in 1655 by the Dutch astronomer Christiaan Huygens, Titan was the first known moon of Saturn, and the sixth known planetary satellite. Titan orbits Saturn at 20 Saturn radii. From Titan's surface Saturn subtends an arc of 5.7 degrees and would appear 11.4 times the size our moon does to us.

Titan is primarily composed of water ice and rocky material. Much as with Venus before the Space Age, the dense opaque atmosphere prevented understanding of Titan's surface until new information accumulated when the Cassini–Huygens mission arrived in 2004, including the discovery of liquid hydrocarbon lakes in Titan's polar regions. The geologically young surface is generally smooth, with few impact craters, although mountains and several possible cryovolcanoes have been found.

The atmosphere of Titan is largely nitrogen; minor components lead to the formation of methane and ethane clouds and nitrogen-rich organic smog. The climate—including wind and rain—creates surface features similar to those of Earth, such as dunes, rivers, lakes, seas (probably of liquid methane and ethane), and deltas, and is dominated by seasonal weather patterns as on Earth. With its liquids (both surface and subsurface) and robust nitrogen atmosphere, Titan's methane cycle is analogous to Earth's water cycle, although at the much lower temperature of about 94 K (−179.2 °C).

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