Cassini Images Seas on Saturn's Moon Titan

March 13, 2007
Cassini Images Seas on Saturn's Moon Titan
A comparison view of a lake on Titan and Lake Superior. Image credit: NASA/JPL/GSFC

Instruments on NASA's Cassini spacecraft have found evidence for seas, likely filled with liquid methane or ethane, in the high northern latitudes of Saturn's moon Titan. One such feature is larger than any of the Great Lakes of North America and is about the same size as several seas on Earth.

Cassini's radar instrument imaged several very dark features near Titan's north pole. Much larger than similar features seen before on Titan, the largest dark feature measures at least 39,000 square miles. Since the radar has caught only a portion of each of these features, only their minimum size is known. Titan is the second largest moon in the solar system and is about 50 percent larger than Earth's moon.

"We've long hypothesized about oceans on Titan and now with multiple instruments we have a first indication of seas that dwarf the lakes seen previously," said Dr. Jonathan Lunine, Cassini interdisciplinary scientist at the University of Arizona, Tucson.

While there is no definitive proof yet that these seas contain liquid, their shape, their dark appearance in radar that indicates smoothness and their other properties point to the presence of liquids. The liquids are probably a combination of methane and ethane, given the conditions on Titan and the abundance of methane and ethane gases and clouds in Titan's atmosphere.

Cassini's visual and infrared mapping spectrometer also captured a view of the region, and the team is working to determine the composition of the material contained within these features to test the hypothesis that they are liquid-filled.

The imaging cameras, which provide a global view of Titan, have imaged a much larger, irregular dark feature. The northern end of their image corresponds to one of the radar-imaged seas. The dark area stretches for more than 620 miles in the image, down to 55 degrees north latitude. If the entire dark area is liquid-filled, it would be only slightly smaller than Earth's Caspian Sea. The radar data show details at the northern end of the dark feature similar to those seen in earlier radar observations of much smaller liquid-filled lakes. However, to determine if the entire dark feature is a liquid-filled basin will require investigation through additional radar flyovers later in the mission.

The presence of these seas reinforces the current thinking that Titan's surface must be resupplying methane to its atmosphere, the original motivation almost a quarter century ago for the theoretical speculation of a global ocean on Titan.

Cassini's instruments are peeling back the haze that shrouds Titan, showing high northern latitudes dotted with seas hundreds of miles across, and hundreds of smaller lakes that vary from several to tens of miles.

Due to the new discoveries, team members are repointing Cassini's radar instrument during a May flyby so it can pass directly over the dark areas imaged by the cameras.

Source: NASA

Explore further: Are planets like those in 'Star Wars: Rogue One' really out there? NASA plans to find out

Related Stories

Cassini prepares for 'ring-grazing orbits'

November 22, 2016

A thrilling ride is about to begin for NASA's Cassini spacecraft. Engineers have been pumping up the spacecraft's orbit around Saturn this year to increase its tilt with respect to the planet's equator and rings. And on Nov. ...

Iceberg patrol gains faster updates from orbit

November 10, 2016

The international iceberg patrol service set up after the sinking of the Titanic is now able to track drifting ice from orbit more swiftly through ESA-backed cloud computing.

Treating chronic, unremitting grief

November 15, 2016

After Stephanie Muldberg's 13-year-old son Eric died of Ewing's sarcoma in 2004, she was lost in a sea of grief. Her days were long, unstructured, monotonous. She barely left her New Jersey home. When she did leave, she planned ...

Saturn's moon Titan

October 5, 2015

In ancient Greek lore, the Titans were giant deities of incredible strength who ruled during the legendary Golden Age and gave birth to the Olympian gods we all know and love. Saturn's largest moon, known as Titan, is therefore ...

Titan's Seas Are Sand

May 4, 2006

Until a couple of years ago, scientists thought the dark equatorial regions of Titan might be liquid oceans. New radar evidence shows they are seas -- but seas of sand dunes like those in the Arabian or Namibian Deserts, ...

Recommended for you

Image: Wavemaker moon Daphnis

January 20, 2017

The wavemaker moon, Daphnis, is featured in this view, taken as NASA's Cassini spacecraft made one of its ring-grazing passes over the outer edges of Saturn's rings on Jan. 16, 2017. This is the closest view of the small ...

Astronomers search for signs of life on Wolf 1061 exoplanet

January 19, 2017

Is there anybody out there? The question of whether Earthlings are alone in the universe has puzzled everyone from biologists and physicists to philosophers and filmmakers. It's also the driving force behind San Francisco ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.