Subscribe free to our newsletters via your
. Saturn News .

Saturn'S Moon Enceladus Hosts A Global Ocean
by Staff Writers
Mountain View CA (SPX) Sep 16, 2015

Illustration of the interior of Saturn's moon Enceladus showing a global liquid water ocean between its rocky core and icy crust. Thickness of layers shown here is not to scale. Image courtesy NASA/JPL-Caltech.

Every square inch of Saturn's small moon Enceladus overlies a potentially habitable ocean. Observations of Enceladus' slight wobble as it orbits Saturn can only be explained if the outer crust floats freely from the inner core, according to scientists studying images taken by NASA's Cassini spacecraft. This means there is a globe-spanning ocean beneath Enceladus' icy surface.

Enceladus has been a prime location for studying the potential for life in the solar system for the past decade, since Cassini found in 2006 a fine spray of water vapor, icy particles, and simple organic molecules erupting from fractures near Enceladus' south pole.

Measurements of the saltiness of geyser particles in 2009 proved that they must emanate from a liquid reservoir, and a 2014 analysis of Enceladus' gravitational pull on the Cassini spacecraft demonstrated that the liquid reservoir is at least a regional sea underlying the entire south pole region. The new results - derived using an independent line of evidence based on Cassini's images - prove that that regional sea is a widening of a global ocean. This discovery is published online in the journal Icarus.

"This exciting discovery expands the region of habitability for Enceladus from just a regional sea under the south pole to all of Enceladus," said Matthew Tiscareno, a Cassini participating scientist at the SETI Institute, Mountain View, California, and a coauthor of the paper. "The global nature of the ocean likely tells us that it has been there for a long time, and is being maintained by robust global effects, which is also encouraging from the standpoint of habitability," he said.

The discovery was made through a combination of imaging, dynamical modeling, and statistical analysis. "This was a hard problem that required years of observations, and calculations involving a diverse collection of disciplines, but we are confident we finally got it right," said Peter Thomas, a Cassini imaging team member at Cornell University, Ithaca, New York, and lead author of the paper.

Enceladus has a tiny, but measurable wobble as it orbits Saturn. The icy moon is not perfectly spherical, and because it goes slightly faster and slower during different parts of its orbit, Saturn pulls and pushes the small moon back and forth as it rotates.

Tiscareno developed a series of dynamical models of this wobble, technically called a libration, and Thomas's group then tested each model against hundreds of Cassini images, taken of Enceladus' surface at different times and from different angles, to find the best fit to the observations with extreme precision. The team plugged their best-fit value for the wobble into different models for how Enceladus might be arranged on the inside, including ones where the moon was frozen from surface to core.

"If the surface and core were rigidly connected, the core would provide so much dead weight that the wobble would be far smaller than we observe it to be," said Tiscareno, "This proves that there must be a global layer of liquid separating the surface from the core," he said.

The geysers deliver samples from this ocean to the surface regularly, which makes Enceladus a prime candidate in the search for life beyond Earth. Although a handful of worlds are now thought to have subsurface oceans, Enceladus joins only Jupiter's moon Europa (which was recently selected as the destination of NASA's next flagship mission) in having an extraterrestrial ocean that is known to communicate with its surface.

"This is a major step beyond what we understood about this moon before, and it demonstrates the kind of deep-dive discoveries we can make with long-lived orbiter missions to other planets," said Carolyn Porco, Cassini imaging team lead at Space Science Institute, Boulder, Colorado, and visiting scholar at the University of California, Berkeley, and a coauthor of the paper. "Cassini has been exemplary in this regard."

Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once

credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly

paypal only


Related Links
SETI Institute
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 DiggDigg RedditReddit GoogleGoogle

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

At Saturn, One of These Rings is not like the Others
Pasadena CA (JPL) Sep 03, 2015
When the sun set on Saturn's rings in August 2009, scientists on NASA's Cassini mission were watching closely. It was the equinox - one of two times in the Saturnian year when the sun illuminates the planet's enormous ring system edge-on. The event provided an extraordinary opportunity for the orbiting Cassini spacecraft to observe short-lived changes in the rings that reveal details about their ... read more

Team Continues to Operate Rover in RAM Mode

Ridley Scott's 'The Martian' takes off in Toronto

Supervising two rovers from space

Mars Panorama from Curiosity Shows Petrified Sand Dunes

Moon's crust as fractured as can be

China aims to land Chang'e-4 probe on far side of moon

China Plans Lunar Rover For Far Side of Moon

Russia Eyes Moon for Hi-Tech Lunar Base

At Saturn, One of These Rings is not like the Others

Discovery of the Origin of Saturn's F Ring and Its Shepherd Satellites

Cassini's Final Breathtaking Close Views of Dione

Cassini to Make Last Close Flyby of Saturn Moon Dione

Long March-2D carrier rocket blasts off in NW China

Progress for Tiangong 2

China rocket parts hit villager's home: police, media

China's "sky eyes" help protect world heritage Angkor Wat

New Pluto Images from New Horizons: It's Complicated

New photos reveal Pluto's stunning geological diversity: NASA

New Horizons Probes the Mystery of Charon's Red Pole

New Horizons Spacecraft begins Intensive Data Downlink Phase

Astronomers peer into the 'amniotic sac' of a planet-hosting star

Rocky planets may be habitable depending on their 'air conditioning system'

Earth observations show how nitrogen may be detected on exoplanets, aiding search for life

Distant planet's interior chemistry may differ from our own

SETI reborn: The New Search for Intelligent Life

Only above-water microbes play a role in cave development

Interstellar seeds could create oases of life

Comet Impacts May Have Led to Life on Earth

Sentinel-2 catches eye of algal storm

First global antineutrino emission map highlights Earth's energy budget

SMAP ends radar operations

Russia to Develop Earth Remote-Sensing Satellite System for Iran

The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news 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 All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.