MOSCOW, Idaho — A team of NASA researchers around the nation, including scientists at the University of Idaho, revealed this week a new view of Saturn’s moon Titan.
With the sun now shining down over 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 Titan’s Earth-like “hydrologic” cycle that involves hydrocarbons rather than water.
“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, an associate professor in the UI Department of Physics who is part of NASA’s Cassini visual and Infrared mapping spectrometer, or VIMS, team. “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.”
Both Barnes and Matt Hedman, an assistant professor of physics at UI, work on the Cassini project as participating scientists in the VIMS team, which has recently released a number of images including a spectacular view of Saturn and its rings backlit by the sun.
Three doctoral students working under Barnes – Graham Vixie, Casey Cook, and Shannon MacKenzie – also work on the project, as well as undergraduate student Corbin Hennen.
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 Cassini’s VIMS and imaging science subsystem have only been able to capture distant, oblique or partial views of this area until now.
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, thankfully, Titan’s beautiful, almost cloudless, rain-free weather continued during Cassini’s flybys this past summer.
The image from VIMS is a mosaic in infrared light based on data obtained during a flyby of Titan on Sept. 12, 2013. The colorized mosaic, which maps infrared colors onto the visible-color spectrum, reveals differences in the composition in 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 here, 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.
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, the Cassini project scientist based at NASA’s Jet Propulsion Laboratory in 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.
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UI Researchers Help Decode New View of Saturn’s Moon Titan, Contribute to Cassini Mission,
