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Ultraviolet observations of the hydrogen coma of comet C/2013 A1 (Siding Spring) by MAVEN/IUVS
Author(s) -
Crismani Matteo M. J.,
Schneider Nicholas M.,
Deighan Justin I.,
Stewart A. Ian F.,
Combi Michael,
Chaffin Michael S.,
Fougere Nicolas,
Jain Sonal K.,
Stiepen Arnaud,
Yelle Roger V.,
McClintock William E.,
Clarke John T.,
Holsclaw Gregory M.,
Montmessin Frank,
Jakosky Bruce M.
Publication year - 2015
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2015gl065290
Subject(s) - comet , astrobiology , photodissociation , aeronomy , mars exploration program , ultraviolet , atmosphere (unit) , physics , meteoroid , hydrogen , coma (optics) , geometric albedo , atmospheric sciences , astronomy , environmental science , meteorology , photochemistry , chemistry , optics , stars , photometry (optics) , quantum mechanics
Abstract We used the Imaging Ultraviolet Spectrograph (IUVS) aboard the Mars Atmosphere and Volatile EvolutioN (MAVEN) orbiting spacecraft to construct images of the hydrogen coma of comet C/2013 A1 (Siding Spring) days before its close encounter with Mars. We obtain a water production rate of 1.1 ± 0.5 × 10 28 molecules/s and determine the total impacting fluence of atoms and molecules corresponding to the photodissociation of water and its daughter species to be 2.4 ± 1.2 × 10 4 kg. We use these observations to confirm predictions that the mass of delivered hydrogen is comparable to the existing reservoir above 150 km. Furthermore, we reconcile disparity between observations and predictions about the detectability of the hydrogen perturbation and thermospheric response.