HR: 13:55h
AN: U23A-02 INVITED     [Abstracts]
TI: Huygens Exploration of Titan - Mission Overview
AU: * Lebreton, J
EM: jean-pierre.lebreton@esa.int
AF: ESA/ESTEC, Research and Scientific Support Department, Noordwijk, 2200 AG Netherlands
AU: Matson, D L
EM: Dennis.L.Matson@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91106 United States
AB: After a 7-year interplanetary trajectory on board the Cassini Orbiter, the Huygens Probe was successfully released on 25 December 2004 for its encounter with Titan 3 weeks later on 14 January 2005. After a descent of about 2« hour under parachute, Huygens safely landed and continued to function flawlessly on the surface for slightly more than 3 hours. Data were received by the Cassini Orbiter for the whole descent and another 72 minutes from the surface. Earth-based radio telescopes received the Huygens carrier for the whole descent and another 3h13min from the surface. During entry, accelerometer measurements enabled the determination of the atmospheric structure profile from an altitude of about 1500 km above the surface down to 160 km. After parachute deployment at 155 km altitude, all instruments were making their measurements. In-situ measurements were made of the atmospheric physical properties, composition and meteorology. Atmospheric haze was observed during the whole descent all the way down to the surface. Clear images of the surface were acquired below 50 km. They revealed a frozen earth-like world where organic chemistry is trapped in a pre-biotic stage. In this world, methane takes the role of water on Earth. Huygens descended over the boundary between a bright icy terrain and a darker terrain covered with cm-size ice-pebbles in a dry river or lake-bed covered with a layer of organic matter. The current reconstructed coordinates of the Huygens landing site (10.3S and 192.7W) may be slightly refined in the next few months when data analysis is progressing and new data about the Huygens landing site are acquired from the Orbiter, in particular from the Orbiter Titan radar in the SAR mode that may narrow down the landing uncertainty to less than 1 km. Huygens is the ESA-provided element of the Cassini-Huygens mission, which is a joint NASA-ESA programme in cooperation with the Italian Space Agency.
DE: 6281 Titan
SC: Union [U]
MN: Fall Meeting 2005