Extreme exospheric dynamics at Charon: Implications for the red spot
Charon's exosphere may exhibit extreme seasonal dynamics, with centuries of quiescence punctuated by short lived (∼4 earth years) exospheric surges near the equinoxes, as spring sunrise bi-annually drives frozen methane off the polar night zones. Charon's pole-centric red spot has been pro...
Published in: | Geophysical Research Letters |
---|---|
Main Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley
2022
|
Subjects: | |
Online Access: | https://doi.org/10.1029/2021GL097580 https://ora.ox.ac.uk/objects/uuid:fb517ff6-5d0a-4dd2-8131-ed3065b71e7c |
id |
ftuloxford:oai:ora.ox.ac.uk:uuid:fb517ff6-5d0a-4dd2-8131-ed3065b71e7c |
---|---|
record_format |
openpolar |
spelling |
ftuloxford:oai:ora.ox.ac.uk:uuid:fb517ff6-5d0a-4dd2-8131-ed3065b71e7c 2023-05-15T18:02:15+02:00 Extreme exospheric dynamics at Charon: Implications for the red spot Teolis, B Raut, U Kammer, JA Gimar, CJ Howett, CJA Gladstone, GR Retherford, KD 2022-07-04 https://doi.org/10.1029/2021GL097580 https://ora.ox.ac.uk/objects/uuid:fb517ff6-5d0a-4dd2-8131-ed3065b71e7c eng eng Wiley doi:10.1029/2021GL097580 https://ora.ox.ac.uk/objects/uuid:fb517ff6-5d0a-4dd2-8131-ed3065b71e7c https://doi.org/10.1029/2021GL097580 info:eu-repo/semantics/openAccess CC Attribution-NonCommercial (CC BY-NC) CC-BY-NC Journal article 2022 ftuloxford https://doi.org/10.1029/2021GL097580 2022-07-07T22:06:05Z Charon's exosphere may exhibit extreme seasonal dynamics, with centuries of quiescence punctuated by short lived (∼4 earth years) exospheric surges near the equinoxes, as spring sunrise bi-annually drives frozen methane off the polar night zones. Charon's pole-centric red spot has been proposed to be the product of Ly-α photolysis of frozen methane into refractory hydrocarbon “tholins”, but the role of exospheric dynamics in the red material's formation has not been investigated. We show with exospheric modeling that methane “polar-swap”, in which exospheric CH4 sublimated from the spring polar zone is rapidly re-frozen onto the autumn hemisphere, deposits ∼30 μm polar frosts too thick for Ly-α light to penetrate. Ethane, the primary methane photoproduct under these conditions, may unlike methane remain frozen decades after polar sunrise under solar wind exposure. Solar wind radiolysis of polar ethane frost synthesizes higher-order refractories that may contribute to the coloration of Charon's polar zones. Article in Journal/Newspaper polar night ORA - Oxford University Research Archive Geophysical Research Letters 49 8 |
institution |
Open Polar |
collection |
ORA - Oxford University Research Archive |
op_collection_id |
ftuloxford |
language |
English |
description |
Charon's exosphere may exhibit extreme seasonal dynamics, with centuries of quiescence punctuated by short lived (∼4 earth years) exospheric surges near the equinoxes, as spring sunrise bi-annually drives frozen methane off the polar night zones. Charon's pole-centric red spot has been proposed to be the product of Ly-α photolysis of frozen methane into refractory hydrocarbon “tholins”, but the role of exospheric dynamics in the red material's formation has not been investigated. We show with exospheric modeling that methane “polar-swap”, in which exospheric CH4 sublimated from the spring polar zone is rapidly re-frozen onto the autumn hemisphere, deposits ∼30 μm polar frosts too thick for Ly-α light to penetrate. Ethane, the primary methane photoproduct under these conditions, may unlike methane remain frozen decades after polar sunrise under solar wind exposure. Solar wind radiolysis of polar ethane frost synthesizes higher-order refractories that may contribute to the coloration of Charon's polar zones. |
format |
Article in Journal/Newspaper |
author |
Teolis, B Raut, U Kammer, JA Gimar, CJ Howett, CJA Gladstone, GR Retherford, KD |
spellingShingle |
Teolis, B Raut, U Kammer, JA Gimar, CJ Howett, CJA Gladstone, GR Retherford, KD Extreme exospheric dynamics at Charon: Implications for the red spot |
author_facet |
Teolis, B Raut, U Kammer, JA Gimar, CJ Howett, CJA Gladstone, GR Retherford, KD |
author_sort |
Teolis, B |
title |
Extreme exospheric dynamics at Charon: Implications for the red spot |
title_short |
Extreme exospheric dynamics at Charon: Implications for the red spot |
title_full |
Extreme exospheric dynamics at Charon: Implications for the red spot |
title_fullStr |
Extreme exospheric dynamics at Charon: Implications for the red spot |
title_full_unstemmed |
Extreme exospheric dynamics at Charon: Implications for the red spot |
title_sort |
extreme exospheric dynamics at charon: implications for the red spot |
publisher |
Wiley |
publishDate |
2022 |
url |
https://doi.org/10.1029/2021GL097580 https://ora.ox.ac.uk/objects/uuid:fb517ff6-5d0a-4dd2-8131-ed3065b71e7c |
genre |
polar night |
genre_facet |
polar night |
op_relation |
doi:10.1029/2021GL097580 https://ora.ox.ac.uk/objects/uuid:fb517ff6-5d0a-4dd2-8131-ed3065b71e7c https://doi.org/10.1029/2021GL097580 |
op_rights |
info:eu-repo/semantics/openAccess CC Attribution-NonCommercial (CC BY-NC) |
op_rightsnorm |
CC-BY-NC |
op_doi |
https://doi.org/10.1029/2021GL097580 |
container_title |
Geophysical Research Letters |
container_volume |
49 |
container_issue |
8 |
_version_ |
1766172036012441600 |