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Titan's Dunes and Other Features Emerge in New Images
Jet Propulsion Laboratory
September 7, 2016

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 (along with a short video) 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.

"Dunes are dynamic features. They're deflected by obstacles along the
downwind path, often making beautiful, undulating patterns," said Jani Radebaugh, a Cassini radar team associate at Brigham Young University
in Provo, Utah.

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.

"This 'annex' looks quite similar to Xanadu using our radar, but there
seems to be something different about the surface there that masks this similarity when observing at other wavelengths, as with Hubble," said
Mike Janssen, also a JPL member of the radar team. "It's an interesting puzzle."

Xanadu -- and now its annex -- remains something of a mystery. Elsewhere
on Titan, mountainous terrain appears in small, isolated patches, but
Xanadu covers a large area, and scientists have proposed a variety of
theories about its formation.

"These mountainous areas appear to be the oldest terrains on Titan, probably remnants of the icy crust before it was covered by organic sediments from
the atmosphere," said Rosaly Lopes, a Cassini radar team member at JPL. "Hiking in these rugged landscapes would likely be similar to hiking in
the Badlands of South Dakota."

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.

"If Cassini were orbiting Earth instead of Saturn, this would be like
getting our last close view of Australia," said Stephen Wall, deputy lead
of the Cassini radar team at NASA's Jet Propulsion Laboratory in Pasadena, California.

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.

The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. JPL, a division of Caltech
in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. JPL designed, developed and assembled the Cassini orbiter.
The radar instrument was built by JPL and the Italian Space Agency, working with team members from the U.S. and several European countries.

More information about Cassini:

http://www.nasa.gov/cassini

http://saturn.jpl.nasa.gov

News Media Contact
Preston Dyches
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-7013
preston.dyches@jpl.nasa.gov

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