title: Ion neutral mass spectrometer results from the first flyby of Titan.
abstract: The Cassini Ion Neutral Mass Spectrometer (INMS) has obtained the first in situ composition measurements of the neutral densities of molecular nitrogen, methane, molecular hydrogen, argon, and a host of stable carbon-nitrile compounds in Titan's upper atmosphere. INMS in situ mass spectrometry has also provided evidence for atmospheric waves in the upper atmosphere and the first direct measurements of isotopes of nitrogen, carbon, and argon, which reveal interesting clues about the evolution of the atmosphere. The bulk composition and thermal structure of the moon's upper atmosphere do not appear to have changed considerably since the Voyager 1 flyby.
authors.affiliation: Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, MI 48109-2143, USA.
authors.forename: J Hunter
authors.initials: JH
authors.lastname: Waite
authors.forename: Hasso
authors.initials: H
authors.lastname: Niemann
authors.forename: Roger V
authors.initials: RV
authors.lastname: Yelle
authors.forename: Wayne T
authors.initials: WT
authors.lastname: Kasprzak
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Cravens
authors.forename: Janet G
authors.initials: JG
authors.lastname: Luhmann
authors.forename: Ralph L
authors.initials: RL
authors.lastname: McNutt
authors.forename: Wing-Huen
authors.initials: WH
authors.lastname: Ip
authors.forename: David
authors.initials: D
authors.lastname: Gell
authors.forename: Virginie
authors.initials: V
authors.lastname: De La Haye
authors.forename: Ingo
authors.initials: I
authors.lastname: Müller-Wordag
authors.forename: Brian
authors.initials: B
authors.lastname: Magee
authors.forename: Nathan
authors.initials: N
authors.lastname: Borggren
authors.forename: Steve
authors.initials: S
authors.lastname: Ledvina
authors.forename: Greg
authors.initials: G
authors.lastname: Fletcher
authors.forename: Erin
authors.initials: E
authors.lastname: Walter
authors.forename: Ryan
authors.initials: R
authors.lastname: Miller
authors.forename: Stefan
authors.initials: S
authors.lastname: Scherer
authors.forename: Rob
authors.initials: R
authors.lastname: Thorpe
authors.forename: Jing
authors.initials: J
authors.lastname: Xu
authors.forename: Bruce
authors.initials: B
authors.lastname: Block
authors.forename: Ken
authors.initials: K
authors.lastname: Arnett
mesh_terms: D001128:Argon; D001272:Atmosphere; D002247:Carbon Isotopes; D004602:Elements; D019419:Evolution, Planetary; D005118:Extraterrestrial Environment; D006838:Hydrocarbons; D006859:Hydrogen; D007554:Isotopes; D013058:Mass Spectrometry; D008697:Methane; D009570:Nitriles; D009584:Nitrogen; D009587:Nitrogen Isotopes; D018539:Saturn; D018531:Spacecraft; D013696:Temperature
chemical_list: D002247:Carbon Isotopes; D004602:Elements; D006838:Hydrocarbons; D007554:Isotopes; D009570:Nitriles; D009587:Nitrogen Isotopes; D001128:Argon; D006859:Hydrogen; D009584:Nitrogen; D008697:Methane