Electric Conductivity And Waves In The Atmosphere Of Titan From The Pwa-hasi Instrument On The Huygens Probe
The descent of the HUYGENS Probe and landing on Titan during the CASSINI-HUYGENS mission (NASA/ESA/ASI) provided outstanding discoveries. Penetrating under the ionospheric top layer, HUYGENS revealed Titan’s atmospheric electricity characteristics that were unaccessible from remote sensing even from the CASSINI orbiter.The Permittivity, Waves and Altimetry (PWA) analyser is a subsystem of HASI (HUYGENS Atmospheric Structure Instrument), an instrument built by a group of european laboratories. This versatile instrument measures the conductivity of the atmosphere with two complementary sensors, a mutual impedance (MI) probe and a relaxation probe (RP) that measures also DC and AC electric fields in passive mode. The preliminary results revealed the lower ionosphere peak of electron density at the altitude of 60 km deduced from our MI and RP measurements, but these results were only qualitative as several difficulties were found in the data analysis procedures. The present work shows the revised procedures deduced from new detailed models and new laboratory tests with spare instruments. In particular the new analysis includes Probe velocity effects, space charge around electrodes, and other minor effects. Electromagnetic waves data in the ranges 0-100 Hz and 0-10 kHz are analysed to search for clues of lightning activity on Titan and possible Schumann resonances. The origin of the high level 36 Hz detected signal, wether natural or artificial, is discussed. The authors acknowledge ASI, CNES, ESTEC, Spanish and Austrian space agencies, which supported the PWA-HASI instrument development and ISSI, Bern, which provided facilities to perform the present work.
AAS/Division for Planetary Sciences Meeting Abstracts #38
- Pub Date:
- December 2006