Mysterious Radio Waves Of Titan
Huygens scored a first in 2005 by measuring the electrical conductivity of Titan's atmosphere. The results hint at a new way to investigate the subsurface layers of Titan and could provide insight into whether or not Titan has a subsurface ocean. The Permittivity, Waves and Altimetry (PWA) sensor on the Huygens Atmosphere Structure Instrument (HASI) detected an extremely low frequency (ELF) radio wave during the descent.
http://www.saturndaily.com/reports/The_Mysterious_Radio_Waves_Of_Titan_999.html