N° 04-2005 - Paris, 18 January 2005<br /><br />More of Titan's secrets to be unveiled on January 21<br /><br />One week after the successful completion of Huygens' mission to the<br />atmosphere and surface of Titan, the largest and most mysterious moon of<br />Saturn, the European Space Agency is bringing together some of the probe's<br />scientists to present and discuss the first results obtained from the data<br />collected by the instruments.<br /><br />After a 4 billion kilometre journey through the Solar System that lasted<br />almost 7 years, the Huygens probe plunged into the hazy atmosphere of Titan<br />at 11h13 CET on January 14 and landed safely on its frozen ground at 13h45<br />CET. It continued transmitting from the surface for several hours, even<br />after the Cassini orbiter dropped below the horizon and stopped recording<br />the data to relay them towards Earth. Cassini received excellent data from<br />the surface of Titan for 1 hour 12 minutes.<br /><br />More than 474 megabits of data were received in 3 hours 44 minutes from<br />Huygens, including some 350 pictures collected during the descent and on the<br />ground, which revealed a landscape apparently modelled by erosion with drain<br />channels, shoreline-like features and even pebble-shaped objects on the<br />surface.<br /><br />The atmosphere was probed and sampled for analysis at altitudes from 160 km<br />to the ground, revealing a uniform mix of methane with nitrogen in the<br />stratosphere. Methane concentration<br /><br />increased steadily in the troposphere down to the surface. Clouds of methane<br />at about 20 km altitude and methane or ethane fog near the surface were<br />detected.<br /><br />The probe's signal, monitored by a global network of radio telescopes on<br />Earth, will help reconstruct its actual trajectory with an accuracy of 1 km<br />and will provide data<br />on Titan's winds. Early analysis of the received signal indicate that<br />Huygens was still transmitting after 3 hours on the surface. Later<br />recordings are being analysed to see how long Huygens kept transmitting from<br />the surface.<br /><br />Samples of aerosols were also collected at altitudes between 125 and 20 km<br />and analysed onboard. During the descent, sounds were recorded in order to<br />detect possible distant thunder from lightning, providing an exciting<br />acoustic backdrop to Huygens's descent.<br /><br />As the probe touched down at about 4.5 m/s, a whole series of instruments<br />provided a large amount of data on the texture of the surface, which<br />resembles wet sand or clay with a thin solid crust, and its composition,<br />mainly a mix of dirty water ice and hydrocarbon ice, resulting in a darker<br />soil than expected. The temperature measured at ground level was about -180<br />degrees Celsius.<br /><br />Some stunning preliminary results were presented shortly after the science<br />teams obtained access to their data, on 15 January. After several days of<br />processing and analysis of these results, the scientists will be able to<br />deliver a better view of this strange distant world during a press<br />conference on Friday 21 January at 11h00 CET at ESA's Headquarters in Paris<br />(rebroadcast at several other ESA establishments). See the attached form.<br /><br />Participating in this event:<br /><br />David Southwood<br />ESA's Director of Science Programmes,<br /><br />Jean-Pierre Lebreton<br />ESA's Huygens Project Scientist and Mission Manager,<br /><br />Marcello Fulchignoni (TBC)<br />Principal Investigator for the Huygens Atmospheric Structure Instrument<br />(HASI), from the University of Paris/Observatoire de Paris-Meudon, France,<br /><br />Martin G. Tomasko<br />Principal Investigator for the Descent Imager and Spectral Radiometer<br />(DISR), from the University of Arizona in Tucson, United States,<br /><br />John C. Zarnecki<br />Principal Investigator for the Surface Science Package (SSP), from the Open<br />University at Milton Keynes, United Kingdom,<br /><br />Guy Israel<br />Principal Investigator for Aerosol Collector and Pyroliser (ACP), from CNRS,<br />Service d'Aéronomie, Verrières-le-Buisson, France<br /><br />Toby Owen<br />Cassini Interdisciplinary Scientist for the atmospheres of Titan and Saturn,<br />from the Institute for Astronomy, Honolulu, United States.<br /><br />The ESA TV service will televise the press conference live via satellite<br />(Eutelsat W1). For transmission details, check http://television.esa.int<br /><br />NASA-TV will broadcast the press conference across the US and as partner in<br />the Cassini-Huygens mission ensure live streaming. For details, see:<br /><br />http://www.nasa.gov/multimedia/nasatv/<br /><br />The Cassini-Huygens mission is a cooperation between NASA, ESA and ASI, the<br />Italian space agency. The Jet Propulsion Laboratory (JPL), a division of the<br />California Institute of Technology in Pasadena, is managing the mission for<br />NASA's Office of Space Science, Washington DC. JPL designed, developed and<br />assembled the Cassini orbiter.