THE VOLATILE COMPOSITION AND ACTIVITY OF COMET 103P/HARTLEY 2 DURING THE EPOXI CLOSEST APPROACH

Journal Article · Fri Jun 10 00:00:00 EDT 2011 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/734/1/L8· OSTI ID:21562589

Dello Russo, N; Vervack, Jr, R J; Lisse, C M; Weaver, H A ^[1]; Kawakita, H; Kobayashi, H ^[2]; Cochran, A L ^[3]; Harris, W M ^[4]; McKay, A J ^[5]; Biver, N; Bockelee-Morvan, D; Crovisier, J ^[6]

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1. Space Department, Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd., Laurel, MD 20723 (United States)
2. Department of Physics, Faculty of Science, Kyoto Sangyo University Motoyama, Kamigamo, Kita-ku, Kyoto 603-8555 (Japan)
3. McDonald Observatory, 1 University Station C1402, Austin, TX 78712-0259 (United States)
4. Department of Applied Sciences, University of California-Davis, One Shields Avenue, Davis, CA 95616 (United States)
5. Astronomy Department, New Mexico State University, Las Cruces, NM 88001 (United States)
6. LESIA, Observatoire de Paris, 5 place Jules Janssen, 92195 Meudon (France)

We report time-resolved measurements of the absolute and relative abundances of eight parent volatiles (H{sub 2}O, CH{sub 3}OH, C{sub 2}H{sub 6}, C{sub 2}H{sub 2}, NH{sub 3}, HCN, H{sub 2}CO, and HC{sub 3}N) in the coma of 103P/Hartley 2 on UT 2010 November 4, the date the EPOXI spacecraft made its closest approach to the comet, using high-dispersion infrared spectroscopy with NIRSPEC at the W. M. Keck Observatory. Overall gas and dust production increased by roughly 60% between UT 10:49 and 15:54. Differences in the spatial distributions of species in the coma suggest icy sources of different composition in the nucleus of 103P/Hartley 2. However, differences in the relative abundances of species with time are minor, suggesting either internal compositional heterogeneity in 103P/Hartley 2 is small compared with the diversity of chemistry observed within the comet population, or more significant heterogeneity exists on scales smaller than our spatial resolution. Observations contemporaneous with the EPOXI encounter test how compositional heterogeneity over the surface and the inner coma of a comet manifests itself in remote-sensing observations of the bulk coma.

• OSTI ID: 21562589
• Journal Information: Astrophysical Journal Letters, Vol. 734, Issue 1; Other Information: DOI: 10.1088/2041-8205/734/1/L8; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ABUNDANCE
AMMONIA
COMETS
DIMETHYL SULFIDE
DUSTS
ETHANE
HYDROCYANIC ACID
INFRARED SPECTRA
METHANOL
NITRILES
SPATIAL DISTRIBUTION
VOLATILITY
WATER
ALCOHOLS
ALKANES
CHALCOGENIDES
DISTRIBUTION
HYDRIDES
HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
INORGANIC ACIDS
INORGANIC COMPOUNDS
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXYGEN COMPOUNDS
SPECTRA
SULFIDES
SULFUR COMPOUNDS