This false-color mosaic, made from infrared data
collected by NASA's Cassini spacecraft, reveals the differences in the
composition of surface materials around hydrocarbon lakes at Titan, Saturn's
largest moon.
Image Credit: NASA/JPL-Caltech/University of Arizona/University
of Idaho
Almost all of the hydrocarbon seas and lakes on the
surface of Saturn's moon Titan cluster around the north pole, as can be seen in
this mosaic from NASA's Cassini mission.
Image Credit: NASA/JPL-Caltech/SSI/JHUAPL/Univ. of
Arizona
Ultracold hydrocarbon lakes and seas (dark shapes)
near the north pole of Saturn's moon Titan can be seen embedded in some kind of
bright surface material in this infrared mosaic from NASA's Cassini mission.
Image Credit: NASA/JPL-Caltech/SSI/JHUAPL/Univ. of
Arizona
The vast hydrocarbon seas and lakes (dark shapes)
near the north pole of Saturn's moon Titan sprawl out beneath the watchful eye
of NASA's Cassini spacecraft.
Image Credit: NASA/JPL-Caltech/SSI/JHUAPL/Univ. of
Arizona
PASADENA, Calif.-- With the sun now shining down over the north pole of
Saturn's moon Titan, a little luck with the weather, and trajectories that put
the spacecraft into optimal viewing positions, NASA's Cassini spacecraft has
obtained new pictures of the liquid methane and ethane seas and lakes that
reside near Titan's north pole. The images reveal new clues about how the lakes
formed and about Titan's Earth-like "hydrologic" cycle, which involves
hydrocarbons rather than water.
The new images are available online at:
While there is one large lake and a few smaller ones near Titan's south pole,
almost all of Titan's lakes appear near the moon's north pole. Cassini
scientists have been able to study much of the terrain with radar, which can
penetrate beneath Titan's clouds and thick haze. And until now, Cassini's visual
and infrared mapping spectrometer and imaging science subsystem had only been
able to capture distant, oblique or partial views of this area.
Several factors combined recently to give these instruments great observing
opportunities. Two recent flybys provided better viewing geometry. Sunlight has
begun to pierce the winter darkness that shrouded Titan's north pole at
Cassini's arrival in the Saturn system nine years ago. A thick cap of haze that
once hung over the north pole has also dissipated as northern summer approaches.
And Titan's beautiful, nearly cloudless, rain-free weather continued during
Cassini's flybys this past summer.
The images are mosaics in infrared light based on data obtained during flybys
of Titan on July 10, July 26, and Sept. 12, 2013. The colorized mosaic from the
visual and infrared mapping spectrometer, which maps infrared colors onto the
visible-color spectrum, reveals differences in the composition of material
around the lakes. The data suggest parts of Titan's lakes and seas may have
evaporated and left behind the Titan equivalent of Earth's salt flats. Only at
Titan, the evaporated material is thought to be organic chemicals originally
from Titan's haze particles that once dissolved in liquid methane. They appear
orange in this image against the greenish backdrop of Titan's typical bedrock of
water ice.
"The view from Cassini's visual and infrared mapping spectrometer gives us a
holistic view of an area that we'd only seen in bits and pieces before and at a
lower resolution," said Jason Barnes, a participating scientist for the
instrument at the University of Idaho, Moscow. "It turns out that Titan's north
pole is even more interesting than we thought, with a complex interplay of
liquids in lakes and seas and deposits left from the evaporation of past lakes
and seas."
The near-infrared images from Cassini's imaging cameras show a bright unit of
terrain in the northern land of lakes that had not previously been visible in
the data. The bright area suggests that the surface here is unique from the rest
of Titan, which might explain why almost all of the lakes are found in this
region. Titan's lakes have very distinctive shapes -- rounded cookie-cutter
silhouettes and steep sides -- and a variety of formation mechanisms have been
proposed. The explanations range from the collapse of land after a volcanic
eruption to karst terrain, where liquids dissolve soluble bedrock. Karst
terrains on Earth can create spectacular topography such as the Carlsbad Caverns
in New Mexico.
"Ever since the lakes and seas were discovered, we've been wondering why
they're concentrated at high northern latitudes," said Elizabeth (Zibi) Turtle,
a Cassini imaging team associate based at the Johns Hopkins Applied Physics
Laboratory, Laurel, Md. "So, seeing that there's something special about the
surface in this region is a big clue to help narrow down the possible
explanations."
Launched in 1997, Cassini has been exploring the Saturn system since 2004. A
full Saturn year is 30 years, and Cassini has been able to observe nearly a
third of a Saturn year. In that time, Saturn and its moons have seen the seasons
change from northern winter to northern summer.
"Titan's northern lakes region is one of the most Earth-like and intriguing
in the solar system," said Linda Spilker, Cassini project scientist, based at
NASA's Jet Propulsion Laboratory, Pasadena, Calif. "We know lakes here change
with the seasons, and Cassini's long mission at Saturn gives us the opportunity
to watch the seasons change at Titan, too. Now that the sun is shining in the
north and we have these wonderful views, we can begin to compare the different
data sets and tease out what Titan's lakes are doing near the north pole."
The Cassini-Huygens mission is a cooperative project of NASA, the European
Space Agency and the Italian Space Agency. JPL manages the mission for NASA's
Science Mission Directorate, Washington. The California Institute of Technology
in Pasadena manages JPL for NASA. The VIMS team is based at the University of
Arizona in Tucson. The imaging operations center is based at the Space Science
Institute in Boulder, Colo.
For more information about the Cassini mission, visit:
and
