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dc.contributor.authorLandis, Margaret E.*
dc.contributor.authorByrne, Shane*
dc.contributor.authorSchörghofer, N.*
dc.contributor.authorSchmidt, Britney E.*
dc.contributor.authorHayne, P. O.*
dc.contributor.authorCastillo-Rogez, J.*
dc.contributor.authorSykes, M. V.*
dc.contributor.authorCombe, J.-P.*
dc.contributor.authorErmakov, Anton I.*
dc.contributor.authorPrettyman, Thomas H.*
dc.contributor.authorRaymond, Carol A.*
dc.contributor.authorRussell, C. T.*
dc.date.accessioned2017-12-21T16:57:17Z
dc.date.available2017-12-21T16:57:17Z
dc.date.issued2017-10
dc.identifier.citationConditions for Sublimating Water Ice to Supply Ceres' Exosphere 2017, 122 (10):1984 Journal of Geophysical Research: Planetsen
dc.identifier.issn21699097
dc.identifier.doi10.1002/2017JE005335
dc.identifier.urihttp://hdl.handle.net/10150/626274
dc.description.abstractObservations of a water vapor exosphere around Ceres suggest that the dwarf planet may be episodically outgassing at a rate of similar to 6 kg s(-1) from unknown sources. With data from the Dawn mission as constraints, we use a coupled thermal and vapor diffusion model to explore three different configurations of water ice (global buried pore-filling ice, global buried excess ice, and local exposed surface ice) that could be present on Ceres. We conclude that a buried ice table cannot alone explain the vapor production rates previously measured, but newly exposed surface ice, given the right conditions, can exceed that vapor production rate. Sublimation lag deposits form that bury and darken this surface ice over a large range of timescales (from < 1 year to approximately hundreds of kyr) that depend on latitude and ice regolith content. Sublimating water vapor can loft regolith particles from the surface of exposed ice, possibly prolonging the visible lifespan of those areas. We find that this process is only effective for regolith grains smaller than approximately ones of microns. Plain Language Summary A thin water vapor atmosphere has been previously detected around Ceres, a dwarf planet in the asteroid belt, from space telescope observations. Based on data collected before the Dawn spacecraft's arrival, Ceres potentially contained a large mass of water ice. However, how that water, frozen within Ceres, could be fueling a tenuous water vapor atmosphere has been previously unknown. We explore the possibility of water vapor coming from either a buried ice table or buried surface ice at the same rate detected by previous observations. We use published data from the Dawn spacecraft mission to compare to our thermal and sublimation models. We conclude that given the right place and time, exposed surface ice can generate enough water vapor to replicate Ceres' tenuous atmosphere.
dc.description.sponsorshipDawn at Ceres Guest Investigator Program award [NNX15AI29G]; NSF Graduate Research Fellowship award [DGE-1143653]en
dc.language.isoenen
dc.publisherAMER GEOPHYSICAL UNIONen
dc.relation.urlhttp://doi.wiley.com/10.1002/2017JE005335en
dc.rights©2017. American Geophysical Union. All Rights Reserved.en
dc.titleConditions for Sublimating Water Ice to Supply Ceres' Exosphereen
dc.typeArticleen
dc.contributor.departmentUniv Arizona, Lunar & Planetary Laben
dc.identifier.journalJournal of Geophysical Research: Planetsen
dc.description.note6 month embargo; published online: 14 Oct 2017.en
dc.description.collectioninformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.en
dc.eprint.versionFinal published versionen
dc.contributor.institutionLunar and Planetary Laboratory; University of Arizona; Tucson AZ USA
dc.contributor.institutionLunar and Planetary Laboratory; University of Arizona; Tucson AZ USA
dc.contributor.institutionInstitute for Astronomy; University of Hawai‘i at Mānoa; Honolulu HI USA
dc.contributor.institutionSchool of Earth and Atmospheric Sciences; Georgia Institute of Technology; Atlanta GA USA
dc.contributor.institutionJet Propulsion Laboratory; California Institute of Technology; Pasadena CA USA
dc.contributor.institutionJet Propulsion Laboratory; California Institute of Technology; Pasadena CA USA
dc.contributor.institutionPlanetary Science Institute; Tucson AZ USA
dc.contributor.institutionBear Fight Institute; Winthrop WA USA
dc.contributor.institutionJet Propulsion Laboratory; California Institute of Technology; Pasadena CA USA
dc.contributor.institutionPlanetary Science Institute; Tucson AZ USA
dc.contributor.institutionJet Propulsion Laboratory; California Institute of Technology; Pasadena CA USA
dc.contributor.institutionSpace Physics Center, Institute of Geophysics and Planetary Physics; University of California; Los Angeles CA USA
html.description.abstractObservations of a water vapor exosphere around Ceres suggest that the dwarf planet may be episodically outgassing at a rate of similar to 6 kg s(-1) from unknown sources. With data from the Dawn mission as constraints, we use a coupled thermal and vapor diffusion model to explore three different configurations of water ice (global buried pore-filling ice, global buried excess ice, and local exposed surface ice) that could be present on Ceres. We conclude that a buried ice table cannot alone explain the vapor production rates previously measured, but newly exposed surface ice, given the right conditions, can exceed that vapor production rate. Sublimation lag deposits form that bury and darken this surface ice over a large range of timescales (from < 1 year to approximately hundreds of kyr) that depend on latitude and ice regolith content. Sublimating water vapor can loft regolith particles from the surface of exposed ice, possibly prolonging the visible lifespan of those areas. We find that this process is only effective for regolith grains smaller than approximately ones of microns. Plain Language Summary A thin water vapor atmosphere has been previously detected around Ceres, a dwarf planet in the asteroid belt, from space telescope observations. Based on data collected before the Dawn spacecraft's arrival, Ceres potentially contained a large mass of water ice. However, how that water, frozen within Ceres, could be fueling a tenuous water vapor atmosphere has been previously unknown. We explore the possibility of water vapor coming from either a buried ice table or buried surface ice at the same rate detected by previous observations. We use published data from the Dawn spacecraft mission to compare to our thermal and sublimation models. We conclude that given the right place and time, exposed surface ice can generate enough water vapor to replicate Ceres' tenuous atmosphere.


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