Cassini takes a close look at Titan (again)

[Rick]

Cassini Data: Saturn Moon May Have Rigid Ice Shell

An analysis of gravity and topography data from the Saturnian moon Titan obtained by NASA's Cassini spacecraft suggests there could be something unexpected about the moon's outer ice shell. The findings, published on Aug. 28 in the journal Nature, suggest that Titan's ice shell could be rigid, and that relatively small topographic features on the surface could be associated with large ice "roots" extending into the underlying ocean.

The study was led by planetary scientists Douglas Hemingway and Francis Nimmo at the University of California, Santa Cruz, who used data from Cassini. The researchers were surprised to find a counterintuitive relationship between gravity and topography.

"Normally, if you fly over a mountain, you expect to see an increase in gravity due to the extra mass of the mountain," said Nimmo, a Cassini participating scientist. "On Titan, when you fly over a mountain, the gravity gets lower. That's a very odd observation."

More: http://www.jpl.nasa.gov/news/news.php?release=2013-261

[Rick]

Cassini Gets New Views of Titan's Land of Lakes

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.

More: http://www.jpl.nasa.gov/news/news.php?release=2013-304

[Rick]

Cassini: Titan Flyby (T-98): Radar Looks for Changes

During this close flyby of Titan, the Cassini Radar will look for changes to the shoreline of Ontario Lacus when compared to the T-57/58 (June/July 2009) and T-65 (January 2010) fly-bys.  The instrument will be used as a synthetic aperture radar, a technique which uses that spacecraft's flight path to simulate a very large radar aperture.

On both approach and departure, the Composite Infrared Spectrometer (CIRS) will map Titan's stratospheric temperatures to monitor seasonal change.  The Imaging Science Subsystem (ISS) will ride along with CIRS to track clouds. On approach, the Visible and Infrared Mapping Spectrometer (VIMS) will ride along to map the lakes and seas of the North Pole; on departure, VIMS will ride along to observe the evolution of the south polar vortex.

More: http://saturn.jpl.nasa.gov/mission/flybys/titan20140202/

[Rick]

Titan Flyby (T-100): the Closest Remaining Brush with Titan

NASA's Cassini spacecraft will whiz past Saturn's smoggy moon Titan on April 7, sniffing the moon's atmosphere as it makes the closest planned pass for the remainder of the mission. Cassini's point of closest approach during the flyby, named "T-100" by mission planners, is targeted at a mere 598 miles (963 kilometers) above the moon's haze-obscured surface.

The close flyby altitude enables Cassini's Ion and Neutral Mass Spectrometer, or INMS, to sample the composition of Titan's upper atmosphere as the spacecraft zooms past. The instrument is capable of determining the chemical, elemental and isotopic composition of the gaseous and volatile components of the neutral particles and the low energy ions in Titan's atmosphere and ionosphere. During this flyby INMS is the prime instrument at closest approach.

More: http://saturn.jpl.nasa.gov/mission/flybys/titan20140407/

[Rick]

Titan's Building Blocks Might Pre-date Saturn

A combined NASA and European Space Agency (ESA)-funded study has found firm evidence that nitrogen in the atmosphere of Saturn's moon Titan originated in conditions similar to the cold birthplace of the most ancient comets from the Oort cloud. The finding rules out the possibility that Titan's building blocks formed within the warm disk of material thought to have surrounded the infant planet Saturn during its formation.

The main implication of this new research is that Titan's building blocks formed early in the solar system's history, in the cold disk of gas and dust that formed the sun. This was also the birthplace of many comets, which retain a primitive, or largely unchanged, composition today.

The research, led by Kathleen Mandt of Southwest Research Institute in San Antonio, was published this week in the Astrophysical Journal Letters. Co-authors on the study include colleagues from France's National Center for Scientific Research (CNRS) and Observatoire de Paris.

More: http://www.jpl.nasa.gov/news/news.php?release=2014-200

[Rick]

Icy Aquifers on Titan Transform Methane Rainfall

The NASA and European Space Agency Cassini mission has revealed hundreds of lakes and seas spread across the north polar region of Saturn's moon Titan. These lakes are filled not with water but with hydrocarbons, a form of organic compound that is also found naturally on Earth and includes methane. The vast majority of liquid in Titan's lakes is thought to be replenished by rainfall from clouds in the moon's atmosphere. But how liquids move and cycle through Titan's crust and atmosphere is still relatively unknown.

A recent study led by Olivier Mousis, a Cassini research associate at the University of Franche-Comté, France, examined how Titan's methane rainfall would interact with icy materials within underground reservoirs. They found that the formation of materials called clathrates changes the chemical composition of the rainfall runoff that charges these hydrocarbon "aquifers." This process leads to the formation of reservoirs of propane and ethane that may feed into some rivers and lakes.

More: http://www.jpl.nasa.gov/news/news.php?release=2014-294

[Rick]

Cassini Watches Mysterious Feature Evolve in Titan Sea

NASA's Cassini spacecraft is monitoring the evolution of a mysterious feature in a large hydrocarbon sea on Saturn's moon Titan. The feature covers an area of about 100 square miles (260 square kilometers) in Ligeia Mare, one of the largest seas on Titan. It has now been observed twice by Cassini's radar experiment, but its appearance changed between the two apparitions.

More: http://www.jpl.nasa.gov/news/news.php?release=2014-327

[Rick]

Swirling Cloud at Titan's Pole is Cold and Toxic

Scientists analyzing data from NASA's Cassini mission have discovered that a giant, toxic cloud is hovering over the south pole of Saturn's largest moon, Titan, after the atmosphere there cooled dramatically.

The scientists found that this giant polar vortex contains frozen particles of the toxic compound hydrogen cyanide, or HCN.

"The discovery suggests that the atmosphere of Titan's southern hemisphere is cooling much faster than we expected," said Remco de Kok of Leiden Observatory and SRON Netherlands Institute for Space Research, lead author of the study published today in the journal Nature.

More: http://www.jpl.nasa.gov/news/news.php?release=2014-331

[Rick]

Cassini Finds Methane Ice Cloud in Titan's Stratosphere

NASA scientists have identified an unexpected high-altitude methane ice cloud on Saturn's moon Titan that is similar to exotic clouds found far above Earth's poles.

This lofty cloud, imaged by NASA's Cassini spacecraft, was part of the winter cap of condensation over Titan's north pole. Now, eight years after spotting this mysterious bit of atmospheric fluff, researchers have determined that it contains methane ice, which produces a much denser cloud than the ethane ice previously identified there.

"The idea that methane clouds could form this high on Titan is completely new," said Carrie Anderson, a Cassini participating scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the study. "Nobody considered that possible before."

More: http://www.jpl.nasa.gov/news/news.php?feature=4354

[Rick]

Cassini Sees Sunny Seas on Titan

As it soared past Saturn's large moon Titan recently, NASA's Cassini spacecraft caught a glimpse of bright sunlight reflecting off hydrocarbon seas.

In the past, Cassini had captured, separately, views of the polar seas and the sun glinting off them, but this is the first time both have been seen together in the same view.

The image is available at:

http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA18432

More: http://www.jpl.nasa.gov/news/news.php?feature=4359

[Mike]

I think these images are incredible and i'm amazed how close they look to sci-fi's ideas of how an alien world would look. Just makes you wonder what else is out there to be discovered.

[Rick]

Cassini Sails into New Ocean Adventures on Titan

NASA's Cassini mission continues its adventures in extraterrestrial oceanography with new findings about the hydrocarbon seas on Saturn's moon Titan. During a flyby in August, the spacecraft sounded the depths near the mouth of a flooded river valley and observed new, bright features in the seas that might be related to the mysterious feature that researchers dubbed the "magic island."

The findings are being presented this week at the Division for Planetary Sciences Meeting of the American Astronomical Society held in Tucson, Arizona.

To the delight of Cassini scientists, two new bright features appeared in Titan's largest sea, Kraken Mare, during the August 21 flyby. In contrast to a previously reported bright, mystery feature in another of Titan's large seas, Ligeia Mare, the new features in Kraken Mare were observed in both radar data and images from Cassini's Visible and Infrared Mapping Spectrometer (VIMS). Having observations at two different wavelengths provides researchers with important clues to the nature of these enigmatic objects.

More: http://www.jpl.nasa.gov/news/news.php?feature=4369

[Rick]

UT Research Offers Explanation for Titan Dune Puzzle

Titan, Saturn's largest moon, is a peculiar place. Unlike any other moon, it has a dense atmosphere. It has rivers and lakes made up of components of natural gas, such as ethane and methane. It also has windswept dunes that are hundreds of yards high, more than a mile wide and hundreds of miles long—despite data suggesting the body to have only light breezes.

Research led by Devon Burr, an associate professor in UT's Earth and Planetary Sciences Department, shows that winds on Titan must blow faster than previously thought to move sand. The discovery may explain how the dunes were formed.

More: http://tntoday.utk.edu/2014/12/08/ut-research-offers-explanation-titan-dune-puzzle/

[Rick]

A New Way to View Titan: 'Despeckle' It

During 10 years of discovery, NASA's Cassini spacecraft has pulled back the smoggy veil that obscures the surface of Titan, Saturn's largest moon. Cassini's radar instrument has mapped almost half of the giant moon's surface; revealed vast, desert-like expanses of sand dunes; and plumbed the depths of expansive hydrocarbon seas. What could make that scientific bounty even more amazing? Well, what if the radar images could look even better?

Thanks to a recently developed technique for handling noise in Cassini's radar images, these views now have a whole new look. The technique, referred to by its developers as "despeckling," produces images of Titan's surface that are much clearer and easier to look at than the views to which scientists and the public have grown accustomed.

Typically, Cassini's radar images have a characteristic grainy appearance. This "speckle noise" can make it difficult for scientists to interpret small-scale features or identify changes in images of the same area taken at different times. Despeckling uses an algorithm to modify the noise, resulting in clearer views that can be easier for researchers to interpret.

More: http://www.jpl.nasa.gov/news/news.php?feature=4483

[Rick]

Dissolving Titan

Saturn's moon Titan is home to seas and lakes filled with liquid hydrocarbons, but what makes the depressions they lie in? A new study suggests that the moon's surface dissolves in a similar process that creates sinkholes on Earth.

Apart from Earth, Titan is the only body in the Solar System known to possess surface lakes and seas, as seen by the international Cassini mission. But at roughly –180°C, the surface of Titan is very cold and liquid methane and ethane, rather than water, dominate the 'hydrological' cycle.

Indeed, methane and ethane-filled topographic depressions are distinctive features near the moon's poles. Two forms have been identified by Cassini. There are vast seas several hundred kilometres across and up to several hundred metres deep, fed by river-like dendritic channels. Then there are numerous smaller, shallower lakes, with rounded edges and steep walls, and generally found in flat areas. Many empty depressions are also observed.

More: http://www.esa.int/Our_Activities/Space_Science/Dissolving_Titan