Changes in surface brightness on Titan observed over four years by NASA’s Cassini spacecraft have added to evidence that cryovolcanism is active on Saturn’s largest Moon. Anezina Solomonidou has presented results at the European Planetary Science Congress (EPSC) 2013 in London. The authors compared many volcanic-like features, such as flows, calderas and craters, with similar geological features found on the Earth to study the possibility of cryovolcanic activity within regions observed close to Titan’s equator.
Titan has an atmosphere rich in organic carbon-based compounds and astronomers believe that beneath its icy surface there is an ocean of liquid water, possibly mixed with ammonia. The low number of impact craters seen on Titan suggests that the surface is relatively young and is therefore dynamic and active. Titan has clouds and rains of liquid methane that mimic Earth’s water cycle. Its landscape is remarkably Earth-like with dunes and lakes, erosion due to weathering and tectonic-like features.
“All of these features, plus a need for a methane reservoir and volcanic activity to replenish the methane in the atmosphere, is compatible with the theory of active cryovolcanism on Titan,” explained Solomonidou, of the Observatoire de Paris and National and Kapodistrian University of Athens.
Solomonidou and colleagues investigated the potentially cryogenic regions of Tui Regio, Hotei Regio and Sotra Patera using Cassini’s Visual and Infrared Mapping Spectrometer (VIMS).
“We were able to penetrate the atmosphere with VIMS and view any changes in these surface features. Interestingly, the albedo (brightness) of two of the areas has changed with time,” explained Solomonidou. “Tui Regio got darker from 2005 to 2009 and Sotra Patera — the most favourable cryovolcanic candidate on Titan — got brighter between 2005 and 2006.”
Surface variations, together with spectral albedo properties and the presence of volcanic-like features, suggest that these cryovolcanic candidate regions are connected to Titan’s deep liquid ocean.
“These results have important implications for Titan’s potential to support life as these cryovolcanic areas might contain environments that could harbour conditions favourable for life,” said Solomonidou.
Images
1. (a) Sand dunes on Titan (upper) (NASA/JPL), Namimbian sand dunes-terrestrial analogue (lower) (NASA/JPL); (b) Short, stubby drainage channels leading to a ‘shoreline’ or boundary of some sort (left) (ESA/NASA/JPL/University of Arizona). Volcan Colima drainage network in Mexico (right) (NASA).
2. Cryovolcanic candidate ‘Sotra Patera’ on Titan has a deep crater (1km) and a significantly high mountain. (Image credit: NASA/JPL Caltech/USGS/University of Arizona). The Kirishima volcano in Japan, a terrestrial analogue (Image credit: USGS).
Contacts
Anezina Solomonidou
Observatoire de Paris/National and Kapodistrian University of Athens.
asolomonidou@geol.uoa.gr
Notes for editors
About the European Planetary Science Congress (EPSC)
EPSC is the major European meeting on planetary science. EPSC 2013 is taking place at University College London (UCL) from Sunday 8 September to Friday 13 September 2013. It is the first time that the Congress has been held in the UK. The 2013 programme includes around 75 sessions and workshops. Details of the Congress and a full schedule of EPSC 2013 scientific sessions and events can be found at the official website: http://www.epsc2013.eu/
EPSC 2013 is organised by Europlanet, UCL and Copernicus Meetings and the event is sponsored by the UK Space Agency, UCL, Astrium and the Science and Technology Facilities Council.
To celebrate EPSC coming to London, a ‘Festival of the Planets’ has been organised across the Capital in collaboration with partners including the Baker Street Irregular Astronomers, the Bloomsbury Theatre, the British Astronomical Association, the British Interplanetary Society, the Natural History Museum, the Open University, Queen Mary University of London, the Royal Astronomical Society, Royal Museums Greenwich and University College London. More information about the events can be found at:
http://www.europlanet-eu.org/epsc2013/outreach-activities
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About Europlanet
Europlanet is a network of planetary scientists, whose aim is to bring together the disparate European community so that Europe can play a leading role in space exploration. Europlanet’s activities complement the mission activities of the European Space Agency through field work at planetary-analogue terrains on Earth, laboratory measurements, computer modelling and observations from ground-based telescopes. Founded in 2002 and funded by the European Commission from 2005-2012, Europlanet has evolved into a community-based organisation that will carry on this work and plan for future missions and mission support.
www.europlanet-eu.org
About UCL (University College London)
Founded in 1826, UCL was the first English university established after Oxford and Cambridge, the first to admit students regardless of race, class, religion or gender and the first to provide systematic teaching of law, architecture and medicine.
UCL is among the world’s top universities, as reflected by its performance in a range of international rankings and tables. According to the Thomson Scientific Citation Index, UCL is the second most highly cited European university and the 15th most highly cited in the world.
UCL has nearly 27,000 students from 150 countries and more than 9,000 employees, of whom one third are from outside the UK. The university is based in Bloomsbury in the heart of London, but also has two international campuses – UCL Australia and UCL Qatar. Its annual income is more than £800 million.
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