Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor
. 24/7 Space News .




SATURN DAILY
A Water Ocean on Titan
by Charles Q. Choi
for Astrobiology Magazine
Moffett Field CA (SPX) May 06, 2011


This artist's illustration shows the likely interior structure of Saturn's moon Titan. The cool and sluggish interior failed to separate into completely differentiated layers of ice and rock. In addition to the hazy surface of Titan (yellow), the layers in the cutaway show an ice layer starting near the surface (light gray), an internal ocean (blue), another layer of ice (light gray) and the mix of rock and ice in the interior (dark gray). In the background are the Cassini spacecraft and Saturn, not to scale. Image credit: NASA/JPL

Oddities in the rotation of Saturn's largest moon Titan might add to growing evidence that it harbors an underground ocean, researchers suggest. Titan, which is larger than Mercury, is the only world besides Earth known to have liquid on its surface. Its seas, made of liquid methane instead of water, have often led to speculation as to whether or not they could host life.

In addition to its seas on its surface, scientists recently also discovered hints that Titan possesses an internal ocean, one of water and ammonia. Using radar to peer through Titan's dense atmosphere, NASA's Cassini spacecraft found that over time, a number of prominent surface features had shifted from their expected positions by up to 19 miles (30 kilometers), showing that the crust was moving and suggesting that it rested on liquid.

Now Cassini's gravity and radar observations of Titan have discovered more clues that it might have an underground sea.

Titan apparently has an orbit very similar to our moon's - for instance, it always presents the same face toward its planet.

However, they noted that Titan's axis of rotation was tilted by about 0.3 degrees. This tilt, or obliquity, seems high, given the estimate of Titan's moment of inertia, or its resistance to changes to its rotation.

One implausible reason for these findings is that Titan is a solid body that is denser near the surface than at its center. "This is in contradiction with all we know about others planets and satellites and planetary formation processes," said researcher Rose-Marie Baland, a planetary scientist at the Royal Observatory of Belgium in Brussels.

Another more likely explanation is that Titan is not solid all the way through, but has an icy shell overlying a liquid water ocean, an icy mantle and an icy, rocky core. The research team's models can give a wide range of thicknesses for the liquid ocean, anywhere from three to 265 miles (five to 425 km), as well as for the icy shell, anywhere from 90 to 125 miles (150 to 200 km).

"We found it very exciting to use some measurements that seem in contradiction and to try to reconcile them," Baland said. "It was like putting together pieces of a puzzle."

Still, the case for Titan having an underground ocean is not closed yet. Its orbit and rotation might also be explained by a recent disturbance, such as a collision with a comet or asteroid.

"Our analysis strengthens the possibility that Titan has a subsurface ocean, but it does not prove it undoubtedly," Baland told Astrobiology Magazine. "So there is still work to do."

Since life as we know it needs liquid water, if Titan does have a subsurface water ocean that may increase the chances the moon could harbor alien life.

In the future, Baland noted that she and her colleagues would like to use this method to analyze Jupiter's four largest satellites, the Galilean moons - Io, Europa, Ganymede and Callisto.

"The measurement of the obliquity of Europe or Ganymede could bring additional evidence for subsurface liquid layers," Baland said.

Baland and her colleagues will detail their findings in a forthcoming issue of the journal Astronomy and Astrophysics.

.


Related Links
Cassini
Explore The Ring World of Saturn and her moons
Jupiter and its Moons
The million outer planets of a star called Sol
News Flash at Mercury






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





SATURN DAILY
Titan Shaped By Weather Not Ice Volcanoes
Pasadena CA (JPL) Apr 11, 2011
Have the surface and belly of Saturn's smog-shrouded moon, Titan, recently simmered like a chilly, bubbling cauldron with ice volcanoes, or has this distant moon gone cold? In a newly published analysis, a pair of NASA scientists analyzing data collected by the Cassini spacecraft suggest Titan may be much less geologically active than some scientists have thought. In the paper, published i ... read more


SATURN DAILY
BRP To Contribute To Canadian Moon And Mars Exploration Programs

Naveen Jain Co-Founder And Chairman Of Moon Express

Project Morpheus To Begin Testing At NASA's Johnson Space Center

NASA Announces Winners Of 18th Annual Great Moonbuggy Race

SATURN DAILY
Opportunity Images Small Craters

Exploring Rio Tinto Eurobotically

NASA Orbiter Reveals Big Changes in Mars' Atmosphere

Dry ice find hints Mars was a wetter place: study

SATURN DAILY
NASA Selects Investigations for Future Key Missions

Space Adventures Reflects Upon A Decade In Space Tourism

Orbital Space Tourism Demand

ISS Orbit raised to help crew return to Earth

SATURN DAILY
Top Chinese scientists honored with naming of minor planets

China sees smooth preparation for launch of unmanned module

China to attempt first space rendezvous

Countdown begins for Chineses space station program

SATURN DAILY
Soyuz is in the launch zone at Europe's Spaceport

Progress Docks To ISS

Russia ferries supplies to space

ESA prepares Soyuz for dry roll-out

SATURN DAILY
Arianespace to launch ABS-2 in 2013

GSAT-8 put through its paces

Ariane Ariane 5 enjoys second successful launch for 2011

Ariane rocket launches two telecoms satellites

SATURN DAILY
An Earth as Dense as Lead

Astronomers unveil portrait of 'super-exotic super-Earth'

Tuning Into ExoPlanet Radio

The Shocking Environment Of Hot Jupiters

SATURN DAILY
News Corp. buys videogame news sites from Hearst

Android smartphones widen lead in US market

Four injured in iPad fight at Beijing Apple store

Endeavour's Last Flight a Big Deal to University Research Team




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement