Subscribe free to our newsletters via your
. Saturn News .




SATURN DAILY
Under Saturnian moon's icy crust lies a 'global' ocean
by Melissa Osgood for Cornell News
Ithaca NY (SPX) Sep 16, 2015


File image.

Cornell University researchers have learned that a global ocean lies beneath the moon's thick icy crust by measuring with precision the tiny wobbles of Saturn's moon Enceladus - whose cosmic quavers are detectable only in high-resolution images taken by NASA's Cassini spacecraft.

Cornell planetary scientists have analyzed more than seven years worth of Enceladus images taken by the spacecraft, which has been orbiting Saturn since mid-2004. "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, Cornell research scientist and lead author of "Enceladus' measured physical libration requires a global subsurface ocean," published online by the journal Icarus (September 2015.)

The geologically diverse Enceladus vigorously vents vapor and liquid water from fractures in its icy crust at its south polar region, as discovered early in Cassini's exploration of the Saturn system. However, space scientists were uncertain about the extent of the subsurface water source.

With each Cassini photographic pass, Thomas and others painstakingly pinpointed and measured Enceladus' topographic features - about 5,800 points - by hand. A slight wobble, about a tenth of a degree, was detected, but even this small motion - called a libration - is far larger than if the surface crust were solidly connected to the satellite's rocky core. Thus, the scientists determined that the satellite must have a global liquid layer, far more extensive than the previously inferred regional liquid "sea" beneath the South Pole.

"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 Matthew Tiscareno, who left Cornell in the summer to join the SETI Institute in Mountain View, California. "This proves that there must be a global layer of liquid separating the surface from the core," he said.

"We're just at the start of learning that Enceladus is incredibly interesting," said Joe Burns, Cornell's Irving Porter Church Professor of Engineering, professor of astronomy and dean of the faculty. "Thanks to great spacecraft like Cassini and exquisitely fine measurements, we're seeing things not possible 20 years ago."

For Carolyn Porco, Cassini imaging team lead at Space Science Institute in Boulder, Colorado, this work illustrates complexity and the many different parts of scientific investigation: The primary measurements were marked manually; the geometry is derived from accurate knowledge of spacecraft location, tracking Cassini's radio signal and using its images to locate features on the satellites.

"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 Porco. "Cassini has been exemplary in this regard."

In addition to Thomas, Burns, Tiscareno and Porco, the authors include Radwan Tajeddine, Cornell space sciences researcher; Jonathan Joseph, Cornell programmer; and senior research associates Tom Loredo and Paul Helfenstein.


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
Cornell University
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
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


SATURN DAILY
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

SATURN DAILY
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

SATURN DAILY
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

SATURN DAILY
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

SATURN DAILY
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

SATURN DAILY
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

SATURN DAILY
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

SATURN DAILY
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.