Huygens data released
Data from four of the six instruments gleaned by the European Space Agency (ESA) Huygens probe are now available for general use. ESA's Huygens probe landed on Saturn's largest moon, Titan, on 14 January 2005. The probe performed six experiments, and the data from four of those experiments are now archived in the ESA Planetary Science Archive (PSA), with an additional copy on NASA's Planetary Data System (PDS). 'The release of the Huygens scientific data archive represents a major milestone in the Huygens mission,' said Jean-Pierre Lebreton, Huygens' Project Scientist. This allows any researcher to now use the data set for his or her own projects, in addition to the calibration information and other documentation. 'This achievement is the result of a major effort performed during the last three years by all the Huygens teams, scientists and engineers, from Europe and the United States.' said ESA planetary scientist Olivier Witasse. These data will give students and researchers alike the chance to get their hands dirty with information from the most exciting scientific experiment in history. The data now available are from the following sensors: - The Aerosol Collector and Pyrolyser, which drew in aerosol particles from Titan's atmosphere, vaporising the samples and then analysing the results. Two instruments took samples at different altitudes. - The Gas Chromatograph and Mass Spectrometer analysed the gases in Titan's atmosphere. A mass spectrometer modelled and separated the different molecules. This instrument also analysed some of the gases created by the Aerosol Collector and Pyrolyser. On landing, the instrument measured the composition of Titan's surface, by heating the instrument prior to impact, to vaporise a part of the surface on landing. - The Doppler Wind Experiment was part of the communication system between Huygens and the mother probe Cassini. A highly stable communication link between the two craft allowed exploration of Titan's atmosphere by measuring the Doppler shift in the carrier signal. This experiment may also have detected Huygens swinging beneath its parachute. Ironically, this data was initially lost through the failure of a data channel, but was later reconstructed thanks to careful monitoring by Earth-based radio telescopes. Winds of more than 400 km per hour were recorded. - The Huygens Atmospheric Structure Instrument measured the physical and electrical properties of Titan's atmosphere. Because the aerodynamics of Huygens were already known, wind gusts could be measured, giving clues to Titan's atmospheric density. If Huygens had landed on a liquid, then the bobbing could also have been measured. This instrument also measured the electrical conductivity of the atmosphere, the electromagnetic activity, and on the surface, the 'electric flux density' of the surface. Finally, a microphone recorded sounds from this distant body. Engineering data are also available, while data from the final two instruments - the Descent Imager Spectral Radiometer and Surface Science Package, in addition to Huygens entry and descent trajectory information, are expected to be released in September or October. 'We look forward to any feedback related to these high-quality data,' said Lyle Huber, from the NASA PDS Atmospheres Node.