Subscribe to our free daily newsletters
. 24/7 Space News .




Subscribe to our free daily newsletters



Life Beneath The Ice In The Outer Solar System?

landing on any of the Jovian moons will be an amazing feat
Milton Keynes - Apr 01, 2004
At present, we know of no worlds beyond our Earth where life exists. However, primitive organisms on our planet have evolved and adapted over billions of years, colonising the most inhospitable places.

Since life seems to gain a foothold in the most hostile environments, it seems distinctly possible that living organisms could exist in ice- covered oceans on worlds far from the Sun, according to Dr. David Rothery (Open University), who will be speaking today at the RAS National Astronomy Meeting in Milton Keynes.

Europa is the innermost of Jupiter's large icy satellites. It is slightly smaller than our own Moon, but its rocky interior is hidden beneath a 100 km blanket of ice. There has been much speculation as to whether the ice remains solid right down to the moon's rocky interior, or whether it consists of a thinner ice sheet floating on an ocean of water.

Data from NASA's Galileo spacecraft, which orbited Jupiter from 1995 until 2003, provided detailed insights into Europa's structure that will not be surpassed until the arrival of NASA's Jupiter Icy Moons Orbiter (which may not be until 2023).

The high-resolution Galileo images and other data revolutionised our knowledge of Europa's surface and interior structure, making it seem more likely that the ice is (at least at some times and in some places) relatively thin (much less than 10 km) and overlying a liquid water ocean. The images showed localized areas of 'melt-through' demonstrated by 'chaos' regions, where detached rafts of the icy shell can be seen dispersed in a now-refrozen matrix.

The cause of melt-through is likely to be tidal heating, which is especially strong within Europa because it orbits within the immense gravity of Jupiter and experiences competing tidal pulls from the large, neighbouring moons, Io and Ganymede. This process also powers the widespread volcanic eruptions on Io.

There may be occasional volcanic eruptions onto Europa's ocean floor - rather like a less active, ice-covered version of Io - or, more likely, hot springs where chemically-enriched water heated by passage through the rock re-emerges on the ocean floor.

This sort of environment is currently regarded as the most likely place for life on Earth to have begun, and life on Europa could have arisen in just the same way. If so, life could survive there today, supported by chemical energy in the same way that the 'hydrothermal vents' on Earth's ocean floors support ecosystems that do not depend on sunlight.

"Episodes of tidal heating in some of the Solar System's other icy bodies could equally well have given rise to life, even in such remote bodies as the newly discovered, remote planetoid Sedna if, as has been suggested, it has a satellite with which to interact tidally," said Dr. Rothery. "However, only in the case of Europa, and perhaps a few other satellites of the giant planets, does it seem plausible that life could flourish in the long term."

Related Links
Galileo at JPL
RAS
RAS National Astronomy Meeting
SpaceDaily
Search SpaceDaily
Subscribe To SpaceDaily Express

Gravity Rules: The Nature and Meaning of Planethood
Boulder - Mar 22, 2004
I am a planetary scientist, so you won't find it surprising that this past Monday evening, March 15th, the dinner table conversation at our home eventually turned to the discovery of the largest ever Kuiper Belt Object, Sedna (2003 VB12). When I remarked that I was amused by the fact that some astronomers don't consider Sedna a planet, our teenage daughter Kate joined in-agreeing that Sedna shouldn't be classified a planet.



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






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








The content herein, unless otherwise known to be public domain, are Copyright 1995-2016 - 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.