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Comet Shoemaker‐Levy‐9 impact with Jupiter: Aeronomical predictions
Author(s) -
Cravens T. E.
Publication year - 1994
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 - 10.1029/94gl01070
Subject(s) - jovian , ionosphere , jupiter (rocket family) , comet , atmosphere of jupiter , atmosphere (unit) , water vapor , astrobiology , ion , aeronomy , physics , atmospheric sciences , astronomy , meteorology , planet , space shuttle , quantum mechanics , saturn
The fragments of comet Shoemaker‐Levy‐9 will enter the atmosphere of Jupiter during July 20–26, 1994. Significant amounts of water vapor will be injected into the upper atmosphere of Jupiter either from the comet itself or from the lower atmosphere of Jupiter. The photochemistry of both the neutral gas and the ionosphere will be greatly altered by the influx of this water vapor or the atomic oxygen generated by the dissociation of the water. Enhanced abundances of H 2 O (or other species such as NH 3 ) in the atmosphere above the homopause should persist for at least a year and should be globally distributed. The odd oxygen (i.e., O or H 2 O or OH) associated with the cometary water influx alters the ion chemistry by removing H + ions, which also has the effect of reducing the ionospheric electron density because H + is ordinarily the main ion species in the Jovian ionosphere. The density of H 3 + , both in the auroral and non‐auroral ionosphere, will also be reduced due to presence of water. This ion species has been detected spectroscopically at Jupiter, and a drop in its abundance should be detectable. The major ion species will become H 3 O + which could reach a peak density as high as 10 4 cm −3 in the non‐auroral ionosphere and 10 5 cm −3 in the auroral ionosphere. It should be possible to detect this ion species spectroscopically from Earth‐based observatories.