Skiing on one of Saturn's moons
With the ski season about to kick off in Europe, many winter sports fanatics will be searching for the best 'powder' across the continent's top destinations, from the Alps in central Europe to eastern Europe and Greece. But will any of them think of looking on one of Saturn's moons? According to astronomers in the EUROPLANET RI (Europlanet Research Infrastructure') project, which received EUR 6 million of funding under the 'Research infrastructures' Theme of the EU's Seventh Framework Programme (FP7) 'Capacities' programme, the weather on Enceladus, one of Saturn's moons, has created conditions that would be just perfect for skiing. The scientists were able to see the superfine ice crystals that coat Enceladus's surface by using global and high-resolution mapping techniques from readings taken by the Cassini orbiter, a joint NASA/ESA/ASI spacecraft mission that has been studying the planet Saturn and its many natural satellites since 2004. These measurements of surface layer thicknesses show that ice particles fall back onto the surface of Enceladus in a predictable pattern. According to the findings, these deposits indicate the plumes and their heat source are relatively long-lived features lasting millennia and probably tens of millions years or more; they have blanketed areas of the surface in a thick layer of tiny ice particles. 'The discovery by instruments aboard the Cassini orbiter that there's a currently active plume of icy dust and vapour from Enceladus has revolutionised planetary science. Earlier this year, we published work that showed material from Enceladus's plumes coats the surfaces of Saturn's icy moons. Now, we've uncovered two lines of evidence that point to thick deposits of plume material coating the surface of Enceladus itself,' says Dr Paul Schenk of the Lunar and Planetary Institute, Houston in the United States. He will present these new findings to a joint conference of the European Planetology Network and the American Astronomical Society's Division of Planetary Sciences (DPS), being held in Nantes, France this week. In this previous work, astronomers from the Max Planck Institute and the University of Potsdam found that under the influence of Saturn's gravity, particles were returning to Enceladus in a distinctive pattern. This allowed them to predict that the heaviest accumulation will be along two longitudes on opposite sides of the satellite. Having confirmed plume fallout, the team now wanted to search for actual physical evidence of plume particle accumulation on the surface itself. They used images from Cassini to map the topography of the terrain and to analyse plume formation sites along Enceladus's many canyons, revealing several sites of plume deposits. However it is hard for the scientists to say just how thick these layers are; the models of plume deposition indicate that the rate of deposition on Enceladus is extremely slow by Earth standards, less than a thousandth of a millimetre per year. To accumulate 100 metres of deposits would take a few tens of millions of years or so. Therefore Dr Paul Schenk advises keen future space skiers to hold off dreaming of an 'out of this world' ski experience just yet - no less due to the 'bulky space suits' that would be needed, than to the extremely low gravity (surface gravity on Enceladus is roughly 1% that of Earth's), making conditions a far cry from Val d'Is ère. But in terms of the powder itself, he insists that it would be 'even finer than talcum powder' and most likely 'the finest powder a skier could hope for'. Cassini's mission has now been extended with missions planned for 2012 and 2015, so the team hope that this will give them more insight into the mysterious wintry climate on one of Saturn's most interesting moons. The overall aim of EUROPLANET RI is provide the European planetary science community with a unique research infrastructure, combining access to a suite of state-of-the-art facilities while fostering their joint development and integration in terms of capacity and performance. This research infrastructure will include access to laboratory and field site facilities, advanced modelling, and simulation and data analysis resources. It will also incorporate data produced by space missions and ground-based telescopes, hence maximising the scientific impact of major European space missions and ground-based installations. Access will be provided in two forms. Three coordinated Transnational Access Activities will open to many users the unique range of laboratory- and field-site facilities selected for this project. At the same time, user-friendly web-based access will be provided to the available planetary science data, information and software tools. Four Joint Research Activities will broaden the scope of the infrastructure, opening access to new field sites, offering new models and data analysis tools for users and widening the opportunity of remote data access, by progressively contributing to a Planetary Virtual Observatory. Building on the synergies between its services, joint research activities and networking activities, EUROPLANET RI will provide the ideal scientific and technical environment to fully analyse data from past and present planetary missions, and prepare the next generation of missions. In this way, it will play a vital role in establishing the EU as a leading player in planetary and space exploration. The EUROPLANET RI project brings together partners from Austria, Denmark, Finland, France, Germany, Greece, Hungary, Italy, the Netherlands, Norway, Russia, Spain, Switzerland and the United Kingdom.For more information, please visit:Europlanet Research Infrastructure:http://www.europlanet-eu.org/outreach/
Countries
Austria, Switzerland, Germany, Denmark, Greece, Spain, Finland, France, Hungary, Italy, Netherlands, Norway, Russia, United Kingdom