The NASA/ESA/ASI Cassini spacecraft detected an atmosphere around Enceladus during the fly-bys of 17 February and 9 March 2005. This audio file is based on the data collected from these passes.
Cassini's MAG magnetometer is an instrument built to measure planetary and interplanetary magnetic fields. It was developed for the mission by an international team from Imperial College, University of London, and the University of Cologne, Germany.
During the two close fly-bys of Enceladus, MAG's observations showed a bending of the moon's magnetic field, with the magnetospheric plasma being slowed and deflected by the moon. This indicated that the moon has a significant atmosphere.
MAG also detected the presence of 'ion cyclotron' waves in the vicinity of the moon. These waves are organised fluctuations in the magnetic field that provide information on what electrically charged molecules (ions) are present. This audio file shows the power of these waves near Enceladus.
The Cassini-Huygens mission is a co-operative project of NASA, ESA and ASI, the Italian space agency.