Saturn's Magnetic Personality Rubs Off on Titan
September 11, 2008
Cassini scientists found that Saturn's moon Titan, which has no magnetic field of its own, holds onto remnants of Saturn's magnetic field when it periodically moves out of the magnetosphere of its parent planet. A unique flyby of Titan caught the big moon on one of its excursions outside Saturn's magnetosphere.
Titan's orbital path through Saturn's magnetosphere is depicted on this image of Saturn's magnetosphere, taken by Cassini's Magnetospheric Imaging Instrument in 2004.
"Titan seemed to be dressing up in its parent's magnetic field although it had left Saturn's magnetosphere," said Cesar Bertucci, Cassini scientist on the magnetometer instrument at Institute for Astronomy and Space Physics, Buenos Aires, Argentina. "For the first time, we were able to measure how long this magnetic field stays around Titan's atmosphere after Titan exits Saturn's magnetosphere and is exposed to the sun's magnetic environment.
Titan's orbit keeps the moon within Saturn's magnetosphere most of the time. The sunward side of Saturn's magnetosphere moves, however, and occasionally Titan finds itself outside that magnetic bubble.
Scientists believe that the history of the magnetic field to which Titan is exposed is recorded in the moon's atmosphere like stratified layers of sediments on Earth. "We basically recorded the 'magnetic memory' of Titan's ionized atmosphere," said Bertucci. Cassini observations show that this magnetic memory affects Titan's atmosphere from 20 minutes to 3 hours.
This observation, made on June 13, 2007, provided a unique opportunity for scientists to study the interaction between Titan and the solar wind, which spews from the sun. A paper in the Sept. 12 issue of the journal Science provides more details on this interaction.
Media Contact: Carolina Martinez 818-354-9382
Jet Propulsion Laboratory, Pasadena, Calif.