Ocean May Exist Beneath Titan's Crust

March 20, 2008
An Ocean Runs Through It
This graphic depicts a cross-section of the Saturnian moon Titan. Cassini scientists speculate there may be a layer of liquid water mixed with ammonia about 100 kilometers (62 miles) below the surface of Titan. Image credit: NASA/JPL

NASA's Cassini spacecraft has discovered evidence that points to the existence of an underground ocean of water and ammonia on Saturn's moon Titan. The findings made using radar measurements of Titan's rotation will appear in the March 21 issue of the journal Science.

"With its organic dunes, lakes, channels and mountains, Titan has one of the most varied, active and Earth-like surfaces in the solar system," said Ralph Lorenz, lead author of the paper and Cassini radar scientist at the Johns Hopkins Applied Physics Laboratory in Laurel, Md., "Now we see changes in the way Titan rotates, giving us a window into Titan's interior beneath the surface."

Members of the mission's science team used Cassini's Synthetic Aperture Radar to collect imaging data during 19 separate passes over Titan between October 2005 and May 2007. The radar can see through Titan's dense, methane-rich atmospheric haze, detailing never-before-seen surface features and establishing their locations on the moon's surface.

Using data from the radar's early observations, the scientists and radar engineers established the locations of 50 unique landmarks on Titan's surface. They then searched for these same lakes, canyons and mountains in the reams of data returned by Cassini in its later flybys of Titan. They found prominent surface features had shifted from their expected positions by up to 19 miles. A systematic displacement of surface features would be difficult to explain unless the moon's icy crust was decoupled from its core by an internal ocean, making it easier for the crust to move.

"We believe that about 62 miles beneath the ice and organic-rich surface is an internal ocean of liquid water mixed with ammonia," said Bryan Stiles of NASA's Jet Propulsion Laboratory (JPL) in, Pasadena, Calif. Stiles also is a contributing author to the paper.

The study of Titan is a major goal of the Cassini-Huygens mission because it may preserve, in deep-freeze, many of the chemical compounds that preceded life on Earth. Titan is the only moon in the solar system that possesses a dense atmosphere. The moon's atmosphere is 1.5 times denser than Earth's. Titan is the largest of Saturn's moons, bigger than the planet Mercury.

"The combination of an organic-rich environment and liquid water is very appealing to astrobiologists," Lorenz said. "Further study of Titan's rotation will let us understand the watery interior better, and because the spin of the crust and the winds in the atmosphere are linked, we might see seasonal variation in the spin in the next few years."

Cassini scientists will not have long to wait before another go at Titan. On March 25, just prior to its closest approach at an altitude of 620 miles, Cassini will employ its Ion and Neutral Mass Spectrometer to examine Titan's upper atmosphere. Immediately after closest approach, the spacecraft's Visual and Infrared Mapping Spectrometer will capture high-resolution images of Titan's southeast quadrant.

Source: NASA

Explore further: Pluto's hydrocarbon haze keeps dwarf planet colder than expected

Related Stories

Researchers explore how atoms align in magnetic materials

November 15, 2017

The atoms inside materials are not always perfectly ordered, as usually depicted in models. In magnetic, ferroelectric (or showing electric polarity) and alloy materials, there is competition between random arrangement of ...

Alloys from the laser printer

November 15, 2017

In the future, new designer alloys for aerospace applications can be manufactured using the 3-D laser melting process (Additive Manufacturing). Pioneering work in this field was provided by Empa researcher Christoph Kenel, ...

Scientists reveal 'superbug's' artillery

October 19, 2017

Monash University's Biomedicine Discovery Institute (BDI) researchers have created the first high-resolution structure depicting a crucial part of the 'superbug' Pseudomonas aeruginosa, classified by the WHO as having the ...

Recommended for you

Solar minimum surprisingly constant

November 17, 2017

Using more than a half-century of observations, Japanese astronomers have discovered that the microwaves coming from the sun at the minimums of the past five solar cycles have been the same each time, despite large differences ...

Lava or not, exoplanet 55 Cancri e likely to have atmosphere

November 16, 2017

Twice as big as Earth, the super-Earth 55 Cancri e was thought to have lava flows on its surface. The planet is so close to its star, the same side of the planet always faces the star, such that the planet has permanent day ...

NASA detects solar flare pulses at Sun and Earth

November 16, 2017

When our Sun erupts with giant explosions—such as bursts of radiation called solar flares—we know they can affect space throughout the solar system as well as near Earth. But monitoring their effects requires having observatories ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

alee
not rated yet Mar 21, 2008
The discovery may be profound though more facts are needed to prove the theory.

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.