Liquid water near Europa’s surface a rarity

Ref. PN: EPSC12/04

Europa, the enigmatic moon of Jupiter, is believed to be home to a subsurface ocean of liquid water. However, future missions to explore Europa’s ocean may need to dig deep. Research suggests that water does not stay in a liquid state near Europa’s surface for longer than a few tens of thousands of years – the blink of an eye in geological terms. Klára Kalousová will present this work at the European Planetary Science Congress in Madrid on Tuesday 25 September 2012.

Europa is mainly made from rock and iron, with a water shell around 100km deep beneath a crust of solid ice. The ocean is warmed sufficiently to maintain its liquid state by heat produced as a by-product of gravitational pulling to-and-fro from Jupiter.

Pockets of liquid water could be tantalisingly close to the surface. However, Kalousová, from the University of Nantes and Charles University in Prague, believes these would be short-lived. She explains, “A global water ocean may be present, but relatively deep below the surface – around 25 to 50km. There could be areas of liquid water at much shallower depths, say around 5km, but these would only exist for a few tens of thousands of years before migrating downwards.”

Kalousová reached these conclusions by mathematically modelling mixtures of liquid water and solid ice under different conditions. She found that due to factors such as density and viscosity differences, liquid water migrates rapidly downwards through partially molten ice and eventually reaches the subsurface ocean.

Other locations in our Solar System may be analysed using this work. Kalousová explains, “As well as helping us to better understand Europa’s water cycle, this research could provide insight into icy moons that are geologically active, such as Enceladus, and worlds that have cycles connecting the interior with a surface atmosphere, such as Titan.”

SCIENCE CONTACTS:

Klára Kalousová
Klára Kalousová will be contactable through the EPSC press office from 24 to 28 September.

PRESS CONTACTS:

Anita Heward
EPSC 2012 Press Officer
Europlanet RI
Mob: +44 7756 034243
Email: anita.heward@europlanet-eu.org

EPSC Press office (24-28 September only)
Tel: +34 91 722 3020 (English enquiries)
Tel: +34 91 722 3021 (Spanish enquiries)
Fax: +34 91 722 3022

IMAGES:

Water near Europa’s surface migrates downwards toward an ocean. Credit: K. Kalousová.

This artist’s cutaway view shows our current understanding of Europa’s interior. Credit: NASA/JPL.

Learning more about Europa’s interior processes will help astronomers understand the origin of observed surface features. Credit: NASA/JPL/DLR.

FURTHER INFORMATION

EUROPEAN PLANETARY SCIENCE CONGRESS 2012

The European Planetary Science Congress (EPSC) is the major European meeting on planetary science and attracts scientists from Europe and around the World. The 2012 programme includes more than 50 sessions and workshops. The EPSC has a distinctively interactive style, with a mix of talks, workshops and posters, intended to provide a stimulating environment for discussion.

This year’s meeting will take place at the IFEMA-Feria de Madrid, Spain, from Sunday 23 September to Friday 28 September 2012. EPSC 2012 is organised by Europlanet, a Research Infrastructure funded under the European Commission’s Framework 7 Programme, in association with the European Geosciences Union, with the support of the Centro de Astrobiología of Spain’s Instituto Nacional de Técnica Aeroespacial (CAB-INTA).

Details of the Congress and a full schedule of EPSC 2012 scientific sessions and events can be found at the official website: http://www.epsc2012.eu/

EUROPLANET

The Europlanet Research Infrastructure is a major (€6 million) programme co-funded by the European Union under the Seventh Framework Programme of the European Commission.

The Europlanet Research Infrastructure brings together the European planetary science community through a range of Networking Activities, aimed at fostering a culture of cooperation in the field of planetary sciences, Transnational Access Activities, providing European researchers with access to a range of laboratory and field site facilities tailored to the needs of planetary research, as well as on-line access to the available planetary science data, information and software tools, through the Integrated and Distributed Information Service. These programmes are underpinned by Joint Research Activities, which are developing and improving the facilities, models, software tools and services offered by Europlanet RI.

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