Solar System Exploration Division

Reggie L. Hudson

(RESEARCH AST, FIELDS AND PARTICLES)

Reggie L. Hudson's Contact Card & Information.
Email: reggie.hudson@nasa.gov
Phone: 301.286.6961
Org Code: 691
Address:
NASA/GSFC
Mail Code 691
Greenbelt, MD 20771
Employer:
NASA

Missions & Projects

Brief Bio


Reggie Hudson is a research scientist working at the NASA Goddard Space Flight Center.  To learn more about him, his work, and his colleagues, visit the web pages of the Cosmic Ice Laboratory.

Education


1978 - Ph.D., Physical Chemistry, University of Tennessee (Knoxville, TN)

1974 - A.B., Chemistry and Mathematics, Pfeiffer University (Misenheimer, NC)

Positions/Employment


Research Astrochemist

NASA Goddard Space Flight Center - Greenbelt, Maryland USA

January 2009 - Present

Member of the Cosmic Ice Laboratory research group; Associate Chief for the Astrochemistry Laboratory (2011-2018); Acting Chief for the Planetary Systems Laboratory (2010-2011)


Lecturer

Department of Astronomy, University of Maryland - College Park, Maryland, USA

January 2010 - June 2018


Professor of Chemistry

Eckerd College - St. Petersburg, Florida USA

September 1978 - December 2008

(tenured faculty member)


Visiting Research Professor of Chemistry

University College London - London, England

August 1985 - July 1986

Research Interests


Astrochemistry, Astrobiology, Planetary Science, Physical Chemistry

Chemistry and physics of cosmic ices (cometary, icy satellite, and interstellar)
Radiation chemistry and photochemistry applied to astrochemical problems
Molecular spectroscopy, especially as applied to molecular structure and reactions

Teaching Experience


Courses in physical chemistry, astrobiology, and astronomy
Courses in introductory chemistry and in the history and methods of science
Courses in Eckerd College's Honors Program (served as program's first director)

Professional Societies


American Chemical Society: Chemical Education, Physical, and History Divisions

1974 - Present


Royal Society of Chemistry (U.K.): Education and Faraday Divisions

1986 - Present


American Astronomical Society: Division for Planetary Sciences, Laboratory Astrophysics Division

1998 - Present


American Geophysical Union

2000 - Present


Sigma Xi

1977 - Present

Professional Service


Chair, Astrochemistry Subdivision, American Chemical Society (2016-2017)

Awards


2023 Laboratory Astrophysics Prize (American Astronomical Society, AAS)

John M. Bevan Award for Teaching Excellence and Campus Leadership, September 2008 (Eckerd College)

Lloyd W. Chapin Award for Excellence in Scholarship, September 2005 (Eckerd College)

Selected Publications


Refereed

2024. "Radiation-Driven Destruction of Thiophene and Methyl-Substituted Thiophenes." Astrobiology 24 (11): 1085-1095 [10.1089/ast.2024.0038] [Journal Article/Letter]

2024. "Infrared Spectroscopic and Physical Properties of Methanol Ices—Reconciling the Conflicting Published Band Strengths of an Important Interstellar Solid." The Astrophysical Journal 970 (2): 108 [10.3847/1538-4357/ad47a5] [Journal Article/Letter]

2024. "Sublimation and infrared spectral properties of ammonium cyanide." Icarus 413 116007 [10.1016/j.icarus.2024.116007] [Journal Article/Letter]

2023. "Infrared Spectra and Vapor Pressures of Crystalline C2N2, with Comparisons to Crystalline HCN." The Planetary Science Journal 4 (11): 205 [10.3847/psj/ad0040] [Journal Article/Letter]

2023. "Interstellar tryptophan revisited." Monthly Notices of the Royal Astronomical Society 526 (3): 4051-4053 [10.1093/mnras/stad3058] [Journal Article/Letter]

2023. "Infrared spectra and optical constants of astronomical ices: V. cyclopropane and ethylene oxide." Icarus 396 115499 [10.1016/j.icarus.2023.115499] [Journal Article/Letter]

2023. "Carbon monoxide ices – a semicentennial review and update for crystalline CO along with the first IR spectrum and band strength for amorphous CO." Monthly Notices of the Royal Astronomical Society 522 (2): 3145-3162 [10.1093/mnras/stad1164] [Journal Article/Letter]

2023. "Influences on Infrared Spectra of Benzene Ices for Titan, Comets, and Beyond: Annealings, Artifacts, and Isosbestic Points." The Planetary Science Journal 4 (3): 55 [10.3847/psj/acc337] [Journal Article/Letter]

2022. "Infrared intensities of methyl acetate, an interstellar compound - comparisons of three organic esters." Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 283 121738 [10.1016/j.saa.2022.121738] [Journal Article/Letter]

2022. "Benzene Vapor Pressures at Titan Temperatures: First Microbalance Results." The Planetary Science Journal 3 (5): 120 [10.3847/PSJ/ac67a5] [Journal Article/Letter]

2022. "Radiation-induced D/H Exchange Rate Constants in Aliphatics Embedded in Water Ice." The Astrophysical Journal 929 (2): 7 [10.3847/1538-4357/ac602b] [Journal Article/Letter]

2022. "A New Method for Measuring IR Band Strengths in H2O-Ices: First Results for OCS, H2S, and SO2 ." The Astrophysical Journal Letters [10.3847/2041-8213/ac6b32] [Journal Article/Letter]

2022. "Infrared Spectra and Intensities of Amorphous and Crystalline Allene." ACS Earth and Space Chemistry [10.1021/acsearthspacechem.1c00339] [Journal Article/Letter]

2022. "Infrared Spectral Intensities of Amine Ices, Precursors to Amino Acids." Astrobiology 22 (4): 452-461 [10.1089/ast.2021.0138] [Journal Article/Letter]

2022. "Radiolytic Destruction of Uracil in Interstellar and Solar System Ices." Astrobiology 22 (3): 233-241 [10.1089/ast.2021.0053] [Journal Article/Letter]

2022. "Ammonia Ices Revisited: New IR Intensities and Optical Constants for Solid NH3." The Astrophysical Journal 925 (2): 156 [10.3847/1538-4357/ac3e74] [Journal Article/Letter]

2022. "Crystalline ices – Densities and comparisons for planetary and interstellar applications." Icarus 373 114799 [10.1016/j.icarus.2021.114799] [Journal Article/Letter]

2022. "Direct measurements of infrared intensities of HCN and H2O + HCN ices for laboratory and observational astrochemistry." Monthly Notices of the Royal Astronomical Society 509 (3): 3515-3522 [10.1093/mnras/stab2992] [Journal Article/Letter]

2022. "Infrared Spectra and Optical Constants of Astronomical Ices: IV. Benzene and Pyridine." Icarus [10.1016/j.icarus.2022.114899] [Journal Article/Letter]

2021. "Hydroxylation of Apollo 17 Soil Sample 78421 by Solar Wind Protons ." Journal of Geophysical Research-Planets [https://doi.org/10.1029/2021JE006845] [Journal Article/Letter]

2021. "Laboratory Studies in Support of the Exploration of Ocean Worlds and NASA Missions." Vol. 53, Issue 4 (Planetary/Astrobiology Decadal Survey Whitepapers) 53 (4): [10.3847/25c2cfeb.935e24ec] [Journal Article/Letter]

2021. "Laboratory Studies of Astronomical Ices: Reaction Chemistry and Spectroscopy." Accounts of Chemical Research 54 (2): 280-290 [10.1021/acs.accounts.0c00637] [Journal Article/Letter]

2021. "Infrared spectra and optical constants of astronomical ices: III. Propane, propylene, and propyne." Icarus 354 114033 [10.1016/j.icarus.2020.114033] [Journal Article/Letter]

2020. "A Modified Algorithm and Open-source Computational Package for the Determination of Infrared Optical Constants Relevant to Astrophysics." The Astrophysical Journal 901 (1): 52 [10.3847/1538-4357/abad39] [Journal Article/Letter]

2020. "Infrared band strengths and other properties of amorphous and crystalline dimethyl ether." Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 233 118217 [10.1016/j.saa.2020.118217] [Journal Article/Letter]

2020. "Mid-infrared spectra of dipropargyl ether ices revisited." Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 233 118206 [10.1016/j.saa.2020.118206] [Journal Article/Letter]

2020. "The Radiation Stability of Thymine in Solid H2O." Astrobiology 20 (10): 956-963 [10.1089/ast.2019.2199] [Journal Article/Letter]

2020. "Propanal, an interstellar aldehyde - first infrared band strengths and other properties of the amorphous and crystalline forms." Monthly Notices of the Royal Astronomical Society 494 (4): 4606–4615 [10.1093/mnras/staa1028] [Journal Article/Letter]

2020. "Preparation, identification, and low-temperature infrared spectra of two elusive crystalline nitrile ices." Icarus 338 113548 [10.1016/j.icarus.2019.113548] [Journal Article/Letter]

2020. "Testing Densities and Refractive Indices of Extraterrestrial Ice Components Using Molecular Structures—Organic Compounds and Molar Refractions." The Astrophysical Journal 891 (1): 22 [10.3847/1538-4357/ab6efa] [Journal Article/Letter]

2020. "Quantifying acetaldehyde in astronomical ices and laboratory analogues: IR spectra, intensities, 13C shifts, and radiation chemistry." Monthly Notices of the Royal Astronomical Society [10.1093/mnras/stz3323] [Journal Article/Letter]

2019. "Solid-State Isomerization and Infrared Band Strengths of Two Conformational Isomers of Cyclopropanecarboxaldehyde, a Candidate Interstellar Molecule." ACS Earth and Space Chemistry 3 (7): 1182-1188 [10.1021/acsearthspacechem.9b00058] [Journal Article/Letter]

2019. "Infrared intensities and molar refraction of amorphous dimethyl carbonate – comparisons to four interstellar molecules." Physical Chemistry Chemical Physics 21 (21): 11284-11289 [10.1039/c9cp01709g] [Journal Article/Letter]

2019. "Molecular identifications in experiments with astronomical ice analogues: new data, old strategies, and the N2 + acetone system." Monthly Notices of the Royal Astronomical Society 485 (1): 861-871 [10.1093/mnras/stz254] [Journal Article/Letter]

2019. "Propynal, an interstellar molecule with an exceptionally strong C≡C infrared band – laboratory infrared data and applications." Monthly Notices of the Royal Astronomical Society 482 (3): 4009-4017 [10.1093/mnras/sty2821] [Journal Article/Letter]

2019. "Infrared band strengths for amorphous and crystalline methyl propionate, a candidate interstellar molecule." Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 207 216-221 [10.1016/j.saa.2018.09.032] [Journal Article/Letter]

2018. "Infrared Spectra and Interstellar Sulfur: New Laboratory Results for H2S and Four Malodorous Thiol Ices." The Astrophysical Journal 867 (2): 138 [10.3847/1538-4357/aae52a] [Journal Article/Letter]

2018. "Interstellar Ices and Radiation-induced Oxidations of Alcohols." The Astrophysical Journal 857 (2): 89 [10.3847/1538-4357/aab708] [Journal Article/Letter]

2018. "IR spectra and properties of solid acetone, an interstellar and cometary molecule." Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 193 33-39 [10.1016/j.saa.2017.11.055] [Journal Article/Letter]

2018. "Coloring Jupiter's clouds: Radiolysis of ammonium hydrosulfide (NH 4 SH)." Icarus 302 418-425 [10.1016/j.icarus.2017.10.041] [Journal Article/Letter]

2018. "Radiation chemistry of solid acetone in the interstellar medium – a new dimension to an old problem." Physical Chemistry Chemical Physics 20 (8): 5389-5398 [10.1039/c7cp06431d] [Journal Article/Letter]

2017. "Laboratory Investigations into the Spectra and Origin of Propylene Oxide: A Chiral Interstellar Molecule." The Astrophysical Journal 835 (2): 225 [10.3847/1538-4357/835/2/225] [Journal Article/Letter]

2017. "Infrared spectra and band strengths of amorphous and crystalline N2O." The Journal of Chemical Physics 146 (2): 024304 [10.1063/1.4973548] [Journal Article/Letter]

2016. "What is Eating Ozone? Thermal Reactions between SO2 and O3: Implications for Icy Environments." The Astrophysical Journal 833 (1): L9 [10.3847/2041-8213/833/1/l9] [Journal Article/Letter]

2016. "The Spectrum of Jupiter's Great Red Spot: The Case for Ammonium Hydrosulfide (NH4SH)." Icarus 271 265-268 [10.1016/j.icarus.2016.02.010] [Journal Article/Letter]

2016. "Infrared Spectra and Band Strengths of CH3SH, an Interstellar Molecule." Phys. Chem. Chem. Phys. 18 (36): 25756-25763 [10.1039/c6cp01475e] [Journal Article/Letter]

2015. "First infrared band strengths for amorphous CO2, an overlooked component of interstellar ices." The Astrophysical Journal Letters 808 (2): L40 [Full Text] [10.1088/2041-8205/808/2/L40] [Journal Article/Letter]

2015. "Infrared spectra and optical constants of elusive amorphous methane." Astrophysical Journal Letters 805 (2): L20 [Full Text] [10.1088/2041-8205/805/2/L20] [Journal Article/Letter]

2015. "Activation of weak IR fundamentals of two species of astrochemical interest in the Td point group – the importance of amorphous ices." Physical Chemistry Chemical Physics 17 (19): 12545-12552 [Full Text] [10.1039/C5CP00975H] [Journal Article/Letter]

2015. "The radiation stability of glycine in solid CO2 – In situ laboratory measurements with applications to Mars." Icarus 252 466-472 [Full Text] [10.1016/j.icarus.2015.02.008] [Journal Article/Letter]

2015. "Descent without Modification? The Thermal Chemistry of H2O2 on Europa and Other Icy Worlds." Astrobiology 15 453-461 [10.1089/ast.2014.1195] [Journal Article/Letter]

2015. "Giant-Planet Chemistry: Ammonium Hydrosulfide (NH4SH), its IR Spectra and Thermal and Radiolytic Stabilities." Icarus 258 181–191 [10.1016/j.icarus.2015.06.015] [Journal Article/Letter]

2014. "Infrared Spectra and Optical Constants of Astronomical Ices: II. Ethane and Ethylene." Icarus 243 147-148 [10.1016/j.icarus.2014.09.001] [Journal Article/Letter]

2014. "Infrared Spectra and Optical Constants of Astronomical Ices: I. Amorphous and Crystalline Acetylene." Icarus 228 276-287 [10.1016/j.icarus.2013.08.029] [Journal Article/Letter]

2013. "Irradiated benzene ice provides clues to meteoritic organic chemistry." Icarus 226 (2): 1201-1209 [Full Text] [10.1016/j.icarus.2013.07.033] [Journal Article/Letter]

2013. "Ketene Formation in Interstellar Ices: A Laboratory Study." The Astrophysical Journal 773 773-782 [Journal Article/Letter]

2013. "Low-temperature Thermal Reactions between SO2 and H2O2 and their Relevance to the Jovian Icy Satellites." Icarus 224 257-259 [10.1016/j.icarus.2013.02.005] [Journal Article/Letter]

2013. "Glycine's Radiolytic Destruction in Ices: First in situ Laboratory Measurements for Mars." Astrobiology 13 647-655 [10.1089/ast.2012.0943] [Journal Article/Letter]

2012. "In-situ Measurements of the Radiation Stability of Amino Acids at 15 - 140 K." Icarus 220 647-659 [10.1016/j.icarus.2012.06.001] [Journal Article/Letter]

2012. "Laboratory IR Studies and Astrophysical Implications of C2H2-Containing Binary Ices." The Astrophysical Journal 748 95 [10.1088/0004-637X/748/2/95] [Journal Article/Letter]

2012. "Thermal Regeneration of Sulfuric Acid Hydrates after Irradiation." Icarus 219 561-566 [10.1016/j.icarus.2012.03.023] [Journal Article/Letter]

2011. "Radiolysis of Sulfuric Acid, Sulfuric Acid Monohydrate, and Sulfuric Acid Tetrahydrate and its Relevance to Europa." Icarus 215 370-380 [10.1016/j.icarus.2011.06.008] [Journal Article/Letter]

2010. "Thermally-Induced Chemistry and the Jovian Icy Satellites: A Laboratory Study of the Formation of Sulfur Oxyanions." Geophysical Research Letters 37 19201 [10.1029/2010GL044553] [Journal Article/Letter]

2010. "O-atom Production in Water Ice: Implications for O2 Formation on Icy Satellites." J. Geophys. Res. 115 E10013 [Journal Article/Letter]

2010. "The Formation and Stability of Carbonic Acid on Outer Solar System Bodies." Icarus 210 480-487 [Journal Article/Letter]

2010. "Infrared Spectra and Optical Constants of Nitrile Ices Relevant to Titan's Atmosphere ." Astrophysical Journal - Supplement 191 96-112 [Journal Article/Letter]

2009. "Enigmatic Isovaline: Investigating the Stability, Racemization, and Formation of a Non-Biological Meteoritic Amino Acid." Astronomical Society of the Pacific Bioastronomy 2007: Molecules, Microbes, and Extraterrestrial Life [Full Text] [Article in Book]

2009. "Europa Europa's Surface Composition." University of Arizona Press Europa [Article in Book]

2009. "Ethane Ices in the Outer Solar System: Spectroscopy and Chemistry." Icarus 203 677-680 [Journal Article/Letter]

2008. "Laboratory Studies of the Chemistry of TNO Surface Materials." The Solar System Beyond Neptune [Article in Book]

2008. "Amino Acids from Ion-Irradiated Nitrile-Containing Ices." Astrobiology 8 771-779 [Full Text] [10.1089/ast.2007.0131] [Journal Article/Letter]

2008. "Formation of Interstellar OCS: Radiation Chemistry and IR Spectra of Precursor Ices." Astrophysical Journal 684 1210-1220 [Journal Article/Letter]

2008. "Radiation Chemistry of H2O + O2 Ices." Icarus 194 379-388 [10.1016/j.icarus.2007.10.002] [Journal Article/Letter]

2007. "Ammonia - Water Ice Laboratory Studies Relevant to Outer Solar System Surfaces." Icarus 190 260-273 [10.1016/j.icarus.2007.02.020] [Journal Article/Letter]

2007. "The Radiolysis of SO2 and H2S in Water Ice: Implications for the Icy Jovian Satellites." Icarus 189 409-423 [10.1016/j.icarus.2007.01.018] [Journal Article/Letter]

2006. "Infrared Detection of HO2 and HO3 Radicals in Water Ice." J. Phys. Chem. A 110 7985-7988 [10.1021/jp062765k] [Journal Article/Letter]

2006. "Infrared Spectra and Radiation Stability of H2O2 Ices Relevant to Europa." Astrobiology 6 483-489 [Journal Article/Letter]

2006. "Astrochemistry Examples in the Classroom." Journal of Chemical Education 83 1611-1615 [Journal Article/Letter]

2006. "Production of Complex Molecules in Astrophysical Ices." Astrochemistry: Recent Successes and Current Challenges 231 (Proceedings IAU Sym.): 247-260 [Proceedings]

2005. "Laboratory Evidence for Solid-Phase Protonation of HNCO in Interstellar Ices." Astrophysical Journal - Supplement Series 159 277-281 [Journal Article/Letter]

2005. "IR Characterization and Radiation Chemistry of Glycolaldehyde and Ethylene Glycol Ices." Advances in Space Research 36 184-189 [Journal Article/Letter]

2005. "A Quantitative Study of Proton Irradiation and UV Photolysis of Benzene in Interstellar Environments." Astronomy & Astrophysics 440 391-402 [Journal Article/Letter]

2005. "Laboratory Experiments on Cometary Materials." Comets II 695-717 [Article in Book]

2004. "Ultraviolet Photolysis and Proton Irradiation of Astrophysical Ice Analogs Containing Hydrogen Cyanide." Icarus 170 (1): 202-213 [10.1016/j.icarus.2004.02.005] [Journal Article/Letter]

2004. "Reactions of Nitriles in Ices Relevant to Titan, Comets, and the Interstellar Medium: Formation of Cyanate Ion, Ketenimines, and Isonitriles." Icarus 172 466-478 [10.1016/j.icarus.2004.06.011] [Journal Article/Letter]

2003. "Radiation Products in Processed Ices Relevant to Edgeworth-Kuiper-Belt Objects." Earth, Moon, and Planets 92 291-306 [Journal Article/Letter]

2003. "Solid-Phase Formation of Interstellar Vinyl Alcohol." Astrophysical Journal 586 L107-L110 [Journal Article/Letter]

2003. "Infrared Study of Ion-Irradiated N2-Dominated Ices Relevant to Triton and Pluto: Formation of HCN and HNC." Icarus 161 486-500 [10.1016/S0019-1035(02)00037-4] [Journal Article/Letter]

2002. "The N3 Radical as a Discriminator Between Ion-Irradiated and UV-Photolyzed Astronomical Ices." Astrophysical Journal 568 1095-1099 [Journal Article/Letter]

2001. "The Formation of Cyanate Ion (OCN-) in Interstellar Ice Analogs." The Astrophysical Journal 550 (2): 1140-1150 [10.1086/319799] [Journal Article/Letter]

2001. "Mid- and Far-Infrared Spectroscopic Studies of the Influence of Temperature, Ultraviolet Photolysis, and Ion Irradiation on Cosmic-Type Ices." Spectrochimica Acta A 57 (4): 843-858 [10.1016/S1386-1425(00)00448-0] [Journal Article/Letter]

2001. "Energetic Processing of Laboratory Ice Analogs: UV Photolysis vs. Ion Bombardment." Journal of Geophysical Research: Planets 106 (E12): 33381-33386 [10.1029/2000JE001320] [Journal Article/Letter]

2001. "Radiation Chemical Alterations in Solar System Ices: An Overview." Journal of Geophysical Research: Planets 106 (E12): 33275-33284 [Journal Article/Letter]

2000. "Carbonic Acid Production in H2O:CO2 ices UV Photolysis vs Proton Bombardment." Astronomy & Astrophysics 357 793-800 [Journal Article/Letter]

2000. "New Experiments and Interpretations Concerning the OCN- Band in Interstellar Ice Analogues." Astronomy & Astrophy 357 787-792 [Journal Article/Letter]

2000. "IR Spectra of Irradiated Cometary Ice Analogues Containing Methanol: A New Assignment, a Reassignment, and a Non-Assignment." Icarus 145 661-663 [Journal Article/Letter]

2000. "IR Detection of H2O2 at 80 K in Ion-Irradiated Laboratory Ices Relevant to Europa." Icarus 145 282-288 [Journal Article/Letter]

1999. "Laboratory Studies of the Formation of Methanol and Other Organic Molecules by Water + Carbon Monoxide Radiolysis: Relevance to Comets, Icy Satellites, and Interstellar Ices." Icarus 140 451-461 [Journal Article/Letter]

1998. "Infrared Study of Ion Irradiated Water Ice Mixtures with Organics Relevant to Comets." Icarus 135 518-527 [Journal Article/Letter]

1997. "Hydrocarbon Radiation Chemistry in Ices of Cometary Relevance." Icarus 126 233-235 [Journal Article/Letter]

1995. "Far-IR Spectral Changes Accompanying Proton Irradiation of Solids of Astrochemical Interest." Radiation Physics and Chemistry 45 779-789 [Journal Article/Letter]

1994. "Far-Infrared Spectra of Cosmic-Type Pure and Mixed Ices." Astronomy & Astrophysics Supplement Series 103 45-56 [Journal Article/Letter]

1994. "Infrared Spectra of Crystalline Phase Ices Condensed on Silicate Smokes at T<20K." ApJ Letters 428 L81-L84 [Full Text] [Journal Article/Letter]

1993. "Far-Infrared Investigations of a Methanol Clathrate Hydrate: Implications for Astronomical Observations." Astrophysical Journal Letters 404 L29-L32 [Journal Article/Letter]

1992. "Far-Infrared Spectral Studies of Phase Changes in Water Ice Induced by Proton Irradiation." Astrophysical Journal 401 353-360 [Journal Article/Letter]

1992. "A Far-IR Study of Irradiated Amorphous Ice: An Unreported Oscillation Between Amorphous and Crystalline Phases." Journal of Physical Chemistry 96 6500-6504 [Journal Article/Letter]

1992. "Comments on 'Gas Release from Comets' and Related Trapped-Gas Experiments." Icarus 96 286-288 [Journal Article/Letter]

1991. "An Experimental Study of the Sublimation of Water Ice and the Release of Trapped Gases." Icarus 94 326-332 [Journal Article/Letter]

1988. "Study of S2 in Ices: Implications for Comets." Icarus 74 399-412 [Journal Article/Letter]