Cometary science. Birth of a comet magnetosphere: a spring of water ions

Hans Nilsson; Gabriella Stenberg Wieser; Etienne Behar; Cyril Simon Wedlund; Herbert Gunell; Masatoshi Yamauchi; Rickard Lundin; Stas Barabash; Martin Wieser; Chris Carr; Emanuele Cupido; James L Burch; Andrei Fedorov; Jean-André Sauvaud; Hannu Koskinen; Esa Kallio; Jean-Pierre Lebreton; Anders Eriksson; Niklas Edberg; Raymond Goldstein; Pierre Henri; Christoph Koenders; Prachet Mokashi; Zoltan Nemeth; Ingo Richter; Karoly Szego; Martin Volwerk; Claire Vallat; Martin Rubin

doi:10.1126/science.aaa0571

Cometary science. Birth of a comet magnetosphere: a spring of water ions

Science. 2015 Jan 23;347(6220):aaa0571. doi: 10.1126/science.aaa0571.

Authors

Hans Nilsson¹, Gabriella Stenberg Wieser², Etienne Behar³, Cyril Simon Wedlund⁴, Herbert Gunell⁵, Masatoshi Yamauchi², Rickard Lundin², Stas Barabash², Martin Wieser², Chris Carr⁶, Emanuele Cupido⁶, James L Burch⁷, Andrei Fedorov⁸, Jean-André Sauvaud⁸, Hannu Koskinen⁹, Esa Kallio¹⁰, Jean-Pierre Lebreton¹¹, Anders Eriksson¹², Niklas Edberg¹², Raymond Goldstein⁵, Pierre Henri¹¹, Christoph Koenders¹³, Prachet Mokashi⁷, Zoltan Nemeth¹⁴, Ingo Richter¹³, Karoly Szego¹⁴, Martin Volwerk¹⁵, Claire Vallat¹⁶, Martin Rubin¹⁷

Affiliations

¹ Swedish Institute of Space Physics, Post Office Box 812, 981 28 Kiruna, Sweden. Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Rymdcampus 1, 981 28 Kiruna, Sweden. hans.nilsson@irf.se.
² Swedish Institute of Space Physics, Post Office Box 812, 981 28 Kiruna, Sweden.
³ Swedish Institute of Space Physics, Post Office Box 812, 981 28 Kiruna, Sweden. Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Rymdcampus 1, 981 28 Kiruna, Sweden.
⁴ Aalto University, School of Electrical Engineering, Department of Radio Science and Engineering, Post Office Box 13000, FI-00076 Aalto, Finland.
⁵ Belgian Institute for Space Aeronomy, Avenue Circulaire 3, 1180 Brussels, Belgium.
⁶ Imperial College London, Exhibition Road, London SW7 2AZ, UK.
⁷ Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238, USA.
⁸ Institut de Recherche en Astrophysique et Planétologie, Toulouse, France.
⁹ Department of Physics, University of Helsinki, Post Office Box 64, FI-00014 Helsinki, Finland. Finnish Meteorological Institute, Post Office Box 503, FI-00101 Helsinki, Finland.
¹⁰ Aalto University, School of Electrical Engineering, Department of Radio Science and Engineering, Post Office Box 13000, FI-00076 Aalto, Finland. Finnish Meteorological Institute, Post Office Box 503, FI-00101 Helsinki, Finland.
¹¹ Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), UMR 7328 CNRS-Université d'Orléans, France.
¹² Swedish Institute of Space Physics, Ångström Laboratory, Lägerhyddsvägen 1, Uppsala, Sweden.
¹³ Technicsche Universität-Braunschweig, Institute for Geophysics and Extraterrestrial Physics, Mendelssohnstraße 3, D-38106 Braunschweig, Germany.
¹⁴ Wigner Research Centre for Physics, 1121 Konkoly Thege Street 29-33, Budapest, Hungary.
¹⁵ Space Research Institute, Austrian Academy of Sciences, Schmiedlstraße 6, 8042 Graz, Austria.
¹⁶ Rosetta Science Ground Segment, Science and Robotic Exploration (SRE-OOR), Office A006, European Space Astronomy Centre, Post Office Box 78, 28691 Villanueva de la Cañada, Madrid, Spain.
¹⁷ Physikalisches Institut, University of Bern, Sidlerstraße 5, CH-3012 Bern, Switzerland.

PMID: 25613894
DOI: 10.1126/science.aaa0571

Abstract

The Rosetta mission shall accompany comet 67P/Churyumov-Gerasimenko from a heliocentric distance of >3.6 astronomical units through perihelion passage at 1.25 astronomical units, spanning low and maximum activity levels. Initially, the solar wind permeates the thin comet atmosphere formed from sublimation, until the size and plasma pressure of the ionized atmosphere define its boundaries: A magnetosphere is born. Using the Rosetta Plasma Consortium ion composition analyzer, we trace the evolution from the first detection of water ions to when the atmosphere begins repelling the solar wind (~3.3 astronomical units), and we report the spatial structure of this early interaction. The near-comet water population comprises accelerated ions (<800 electron volts), produced upstream of Rosetta, and lower energy locally produced ions; we estimate the fluxes of both ion species and energetic neutral atoms.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.