HR: 13:40h
AN: P43B-01 INVITED     [Abstracts]
TI: Huygens 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 almost 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 signal during the descent and another 3h13 minutes from the surface. Measurements on the atmosphere structure were performed during the entry from about 1500 km down to 156 km. Measurements about the winds, the atmosphere structure, composition, and dynamics were performed during the descent under parachute below 155 km. The properties of haze below 150 km were obtained down to the surface. Clear surface images were obtained below 50 km. Surface properties were measured during impact and surface composition measurements were made after landing. Huygens 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 deposit. The current reconstructed coordinates of the Huygens landing site (~10.3S and ~192.4W) may be slightly refined in the next few months when data analysis is progressing and new data from the Huygens landing site are acquired from the Orbiter, in particular from the Titan radar in the SAR mode that may allow to narrow down the landing uncertainty to less than 1 km. The Huygens mission is described and the main entry and descent characteristics are reviewed. The measurements performed by the payload are briefly described as an introduction to the more detailed papers in this session. 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: Planetary Sciences [P]
MN: Fall Meeting 2005