Case of the Lost Atmosphere Target Name:   Titan Spacecraft:   Cassini Orbiter Instrument:   Ion and Neutral Mass Spectrometer Produced by:   NASA/JPL/UC Berkeley Copyright:  NASA Copyright Free Policy Cross Reference:   PIA06981 Date Taken:   26 October 2004

• Titan
• Saturn

This graph shows data acquired by Cassini as it flew by Titan at an altitude of 1,200 kilometers (745 miles) on Oct. 26, 2004 - its closet approach yet to the hazy moon. The data is from Cassini's ion and neutral mass spectrometer, which detects charged and neutral particles in the atmosphere. The graph shows that the amount of light nitrogen in the atmosphere of Titan is much less than that around other planets. Scientists believe this nitrogen was lost over large geologic times scales for reasons that remain unknown.