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Constraining models of activity on comet 67P/Churyumov-Gerasimenko with Rosetta trajectory, rotation, and water production measurements

Attree, N. and Jorda, L. and Groussin, O. and Mottola, S. and Thomas, N. and Brouet, Y. and Kührt, E. and Knapmeyer, M. and Preusker, F. and Scholten, F. and Knollenberg, J. and Hviid, S. and Hartogh, P. and Rodrigo, R. (2019) Constraining models of activity on comet 67P/Churyumov-Gerasimenko with Rosetta trajectory, rotation, and water production measurements. Astronomy & Astrophysics, 630, A18. EDP Sciences. DOI: 10.1051/0004-6361/201834415 ISSN 0004-6361

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Official URL: https://www.aanda.org/articles/aa/abs/2019/10/aa34415-18/aa34415-18.html

Abstract

Aims. We use four observational data sets, mainly from the Rosetta mission, to constrain the activity pattern of the nucleus of comet 67P/Churyumov-Gerasimenko (67P). Methods. We developed a numerical model that computes the production rate and non-gravitational acceleration of the nucleus of comet 67P as a function of time, taking into account its complex shape with a shape model econstructed from OSIRIS imagery. We used this model to fit three observational data sets: the trajectory data from flight dynamics; the rotation state as reconstructed from OSIRIS imagery; and the water production measurements from ROSINA of 67P. The two key parameters of our model, adjusted to fit the three data sets all together, are the activity pattern and the momentum transfer efficiency (i.e., the so-called η parameter of the non-gravitational forces). Results. We find an activity pattern that can successfully reproduce the three data sets simultaneously. The fitted activity pattern exhibits two main features: a higher effective active fraction in two southern super-regions (~10%) outside perihelion compared to the northern regions (<4%), and a drastic rise in effective active fraction of the southern regions (~25-35%) around perihelion. We interpret the time-varying southern effective active fraction by cyclic formation and removal of a dust mantle in these regions. Our analysis supports moderate values of the momentum transfer coefficient η in the range 0.6–0.7; values η ≤ 0.5 or η ≥ 0.8 significantly degrade the fit to the three data sets. Our conclusions reinforce the idea that seasonal effects linked to the orientation of the spin axis play a key role in the formation and evolution of dust mantles, and in turn, they largely control the temporal variations of the gas flux.

Item URL in elib:https://elib.dlr.de/131421/
Document Type:Article
Title:Constraining models of activity on comet 67P/Churyumov-Gerasimenko with Rosetta trajectory, rotation, and water production measurements
Authors:
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Attree, N.Earth and Planetary Observation Centre, Faculty of Natural Sciences, University of Stirling, UKUNSPECIFIED
Jorda, L.Laboratoire d’Astrophysique de Marseille, Marseille, FranceUNSPECIFIED
Groussin, O.Aix-Marseille Université, CNRS, LAM (Laboratoire d’Astro- physique de Marseille) UMR 7326, 13388 Marseille, FranceUNSPECIFIED
Mottola, S.stefano.mottola (at) dlr.dehttps://orcid.org/0000-0002-0457-3872
Thomas, N.Physikalisches Institut, Sidlerstrasse 5, University of Bern, CH-3012 Bern, SwitzerlandUNSPECIFIED
Brouet, Y.Physikalisches Institut, Sidlerstrasse 5, University of Bern, CH-3012 Bern, SwitzerlandUNSPECIFIED
Kührt, E.ekkehard.kuehrt (at) dlr.deUNSPECIFIED
Knapmeyer, M.martin.knapmeyer (at) dlr.deUNSPECIFIED
Preusker, F.Frank.Preusker (at) dlr.deUNSPECIFIED
Scholten, F.frank.scholten (at) dlr.deUNSPECIFIED
Knollenberg, J.joerg.knollenberg (at) dlr.deUNSPECIFIED
Hviid, S.stubbe.hviid (at) dlr.deUNSPECIFIED
Hartogh, P.Max-Planck-Institut für Sonnensystemforschung, Katlenburg-LindauUNSPECIFIED
Rodrigo, R.Instituto de Astrofisica de Andalucia, C/ Camino Bajo de Hue´tor 24, 18008 Granada, SpainUNSPECIFIED
Date:2019
Journal or Publication Title:Astronomy & Astrophysics
Refereed publication:Yes
Open Access:Yes
Gold Open Access:No
In SCOPUS:Yes
In ISI Web of Science:Yes
Volume:630
DOI :10.1051/0004-6361/201834415
Page Range:A18
Publisher:EDP Sciences
ISSN:0004-6361
Status:Published
Keywords:planets and satellites: dynamical evolution and stability – comets: individual: 67P/Churyumov-Gerasimenko - comets: general
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Space
HGF - Program Themes:Space Science and Exploration
DLR - Research area:Raumfahrt
DLR - Program:R EW - Erforschung des Weltraums
DLR - Research theme (Project):R - Projekt ROSETTA Instrumente
Location: Berlin-Adlershof
Institutes and Institutions:Institute of Planetary Research > Asteroids and Comets
Institute of Planetary Research > Planetary Geodesy
Institute of Planetary Research > Planetary Physics
Deposited By: Mottola, Dr.phys. Stefano
Deposited On:28 Nov 2019 08:53
Last Modified:07 Jan 2020 09:36

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