Preliminary Analysis of the Extremely Low Frequency Signals Detected With the PWA-HASI Instrument During the Descent of the Huygens Probe Through the Atmosphere of Titan

The Permittivity, Waves, and Altimetry (PWA) analyzer is a subsystem of the Huygens Atmospheric Structure Instrument (HASI), onboard the Huygens Probe. Dedicated to the study of electric phenomena, the PWA instrument measured the electric field in the bandwidth 0-10kHz, during the descent of the Probe through the atmosphere of Titan. A distinctive electric signal is observed at around 36Hz, which may provide information about wave activity in the atmosphere. We present several hypotheses about the nature of this signal, related to natural phenomena taking place in the environment of Titan. It is not believed that the emission at 36Hz is induced by other instruments, the parachutes, or the Probe body. We tentatively assume that this signal is similar to the Schumann resonance observed on Earth, and we test the validity of the data set against the results from a model of the resonance of Titan's ionospheric cavity.