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Cassini Spies Titan's Tallest Peaks
Jet Propulsion Laboratory
March 24, 2016
[Image]
The trio of ridges on Titan known as Mithrim Montes is home to the hazy Saturnian moon's tallest peak. Image credit: NASA/JPL-Caltech/ASI
In a nod to extraterrestrial mountaineers of the future, scientists working
on NASA's Cassini mission have identified the highest point on Saturn's largest moon, Titan.
Titan's tallest peak is 10,948 feet (3,337 meters) high and is found within
a trio of mountainous ridges called the Mithrim Montes. The researchers
found that all of Titan's highest peaks are about 10,000 feet (3,000 meters) in elevation. The study used images and other data from Cassini's radar instrument, which can peer through the obscuring smog of Titan's atmosphere
to reveal the surface in detail.
"It's not only the highest point we've found so far on Titan, but we think it's the highest point we're likely to find," said Stephen Wall, deputy
lead of the Cassini radar team at NASA's Jet Propulsion Laboratory in Pasadena, California.
The results, which use data collected by Cassini's radar instrument, are
being presented today at the 47th annual Lunar and Planetary Science Conference
at The Woodlands, Texas.
Most of Titan's tallest mountains appear to be close to the equator. The researchers identified other peaks of similar height within the Mithrim Montes, as well as in the rugged region known as Xanadu, and in collections
of more isolated peaks called "ridge belts" located near the landing site
of ESA's Huygens probe.
The investigation was originally motivated by a search for active zones
within Titan's crust -- places where dynamic forces have shaped the landscape, perhaps in the relatively recent past.
"As explorers, we're motivated to find the highest or deepest places,
partly because it's exciting. But Titan's extremes also tell us important things about forces affecting its evolution," said Jani Radebaugh, a Cassini radar team associate at Brigham Young University in Provo, Utah, who led
the research.
Mountains and cliffs on Earth usually are found in locations where forces
have shoved the surface upward from underneath. Forces of erosion, including wind, rain and runoff, slowly wear them down over time. The Himalaya and
Andes Mountains are examples of places where interior forces are at work today. The Appalachian Mountains represent much more ancient activity
that produced similarly gigantic peaks long ago, which have since eroded.
Cassini has found that Titan also has rain and rivers that erode its landscape.
According to Radebaugh, the process probably proceeds much more slowly
on Titan than on Earth because, at 10 times Earth's distance from the
sun, there is less energy to power erosive processes in the moon's atmosphere.
Titan's icy crust sits atop a deep ocean of liquid water that probably
acts much like Earth's upper mantle -- the layer of hot, high-pressure
rock below the crust that can slowly flow and deform over time. Once a
period of mountain-building ends, these fluid layers (Earth's upper mantle
and Titan's liquid ocean) allow the crust to relax, like a person settling into a waterbed. Also, at great depth, the water-ice bedrock of Titan
is softer than rock on Earth. Because of these characteristics, scientists didn't expect mountains on Titan would tower quite as high as those on
Earth, which can rise to more than 5 miles (nearly 9 kilometers) tall.
The fact that Titan has significant mountains at all suggests that some
active tectonic forces could be affecting the surface, for example, related
to Titan's rotation, tidal forces from Saturn or cooling of the crust.
The next step for the researchers will be trying to figure out what could produce such tall peaks on an icy ocean world.
"There is lot of value in examining the topography of Titan in a broad,
global sense, since it tells us about forces acting on the surface from
below as well as above," said Radebaugh.
The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology 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 US and several European countries.
More information about Cassini:
http://www.nasa.gov/cassini
http://saturn.jpl.nasa.gov
Media Contact
Preston Dyches
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-7013
preston.dyches@jpl.nasa.gov
2016-083
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