title: Cusp observation at Saturn's high-latitude magnetosphere by the Cassini spacecraft.
abstract: We report on the first analysis of magnetospheric cusp observations at Saturn by multiple in situ instruments onboard the Cassini spacecraft. Using this we infer the process of reconnection was occurring at Saturn's magnetopause. This agrees with remote observations that showed the associated auroral signatures of reconnection. Cassini crossed the northern cusp around noon local time along a poleward trajectory. The spacecraft observed ion energy-latitude dispersions-a characteristic signature of the terrestrial cusp. This ion dispersion is "stepped," which shows that the reconnection is pulsed. The ion energy-pitch angle dispersions suggest that the field-aligned distance from the cusp to the reconnection site varies between ∼27 and 51RS. An intensification of lower frequencies of the Saturn kilometric radiation emissions suggests the prior arrival of a solar wind shock front, compressing the magnetosphere and providing more favorable conditions for magnetopause reconnection.
  
  
  CONCLUSIONS
  We observe evidence for reconnection in the cusp plasma at SaturnWe present evidence that the reconnection process can be pulsed at SaturnSaturn's cusp shows similar characteristics to the terrestrial cusp.
authors.affiliation: Mullard Space Science Laboratory, Department of Space and Climate Physics, University College London Dorking, Surrey, UK ; Centre for Planetary Sciences, UCL/Birkbeck London, UK.
authors.forename: J M
authors.initials: JM
authors.lastname: Jasinski
authors.affiliation: Mullard Space Science Laboratory, Department of Space and Climate Physics, University College London Dorking, Surrey, UK ; Centre for Planetary Sciences, UCL/Birkbeck London, UK.
authors.forename: C S
authors.initials: CS
authors.lastname: Arridge
authors.affiliation: LESIA, Observatoire de Paris, CNRS, UPMC, Université Paris 6, Université Paris Diderot Meudon, France.
authors.forename: L
authors.initials: L
authors.lastname: Lamy
authors.affiliation: Blackett Laboratory, Department of Physics, Imperial College London London, UK.
authors.forename: J S
authors.initials: JS
authors.lastname: Leisner
authors.affiliation: Planetary Science Institute Tucson, Arizona, USA.
authors.forename: M F
authors.initials: MF
authors.lastname: Thomsen
authors.affiliation: Applied Physics Laboratory, Johns Hopkins University Laurel, Maryland, USA.
authors.forename: D G
authors.initials: DG
authors.lastname: Mitchell
authors.affiliation: Mullard Space Science Laboratory, Department of Space and Climate Physics, University College London Dorking, Surrey, UK ; Centre for Planetary Sciences, UCL/Birkbeck London, UK.
authors.forename: A J
authors.initials: AJ
authors.lastname: Coates
authors.affiliation: Laboratoire de Physique Atmosphérique et Planétaire, Institut d'Astrophysique et de Géophysique, Université de Liége Liege, Belgium.
authors.forename: A
authors.initials: A
authors.lastname: Radioti
authors.affiliation: Mullard Space Science Laboratory, Department of Space and Climate Physics, University College London Dorking, Surrey, UK ; Centre for Planetary Sciences, UCL/Birkbeck London, UK.
authors.forename: G H
authors.initials: GH
authors.lastname: Jones
authors.affiliation: Max-Planck-Institut für Sonnensystemforschung Göttingen, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Roussos
authors.affiliation: Max-Planck-Institut für Sonnensystemforschung Göttingen, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Krupp
authors.affiliation: Laboratoire de Physique Atmosphérique et Planétaire, Institut d'Astrophysique et de Géophysique, Université de Liége Liege, Belgium.
authors.forename: D
authors.initials: D
authors.lastname: Grodent
authors.affiliation: Planetary Science Institute Tucson, Arizona, USA.
authors.forename: M K
authors.initials: MK
authors.lastname: Dougherty
authors.affiliation: Southwest Research Institute, Space Science and Engineering Division San Antonio, Texas, USA.
authors.forename: J H
authors.initials: JH
authors.lastname: Waite
keywords: Cassini; cusp; dispersion; plasma; reconnection