Experimental study on the radiation-induced destruction of organic compounds on the surface of the Moon
Volatile organic molecules and a complex organic refractory material were detected on the Moon and on lunar samples. The Moon’s surface is exposed to a continuous flux of solar UV photons and fast ions, e.g. galactic cosmic rays (GCRs), solar wind (SW), and solar energetic particles (SEPs), that m...
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Luleå tekniska universitet
2024
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ftluleatu:oai:DiVA.org:ltu-105195 2024-05-19T07:48:42+00:00 Experimental study on the radiation-induced destruction of organic compounds on the surface of the Moon Dalla Pria, Gaia Lucrezia Sohier, O. Scirè, C. Urso, R. G. Baratta, G. A. Palumbo, M. E. 2024 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-105195 https://doi.org/10.1016/j.icarus.2024.116077 eng eng LuleÃ¥ tekniska universitet INAF-Osservatorio Astrofisico di Catania, Via Santa Sofia 78, Catania, 95123, Italy INAF-Osservatorio Astrofisico di Catania, Via Santa Sofia 78, Catania, 95123, Italy; Université de Versailles Saint-Quentin-en-Yvelines, 55 avenue de Paris, Versailles, 78035, France Icarus, 0019-1035, 2024, 415, http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-105195 doi:10.1016/j.icarus.2024.116077 Scopus 2-s2.0-85190112480 info:eu-repo/semantics/openAccess Astrobiology Astrochemistry Ice spectroscopy Laboratory astrophysics Lunar surface Astronomy Astrophysics and Cosmology Astronomi astrofysik och kosmologi Article in journal info:eu-repo/semantics/article text 2024 ftluleatu https://doi.org/10.1016/j.icarus.2024.116077 2024-04-23T23:31:50Z Volatile organic molecules and a complex organic refractory material were detected on the Moon and on lunar samples. The Moon’s surface is exposed to a continuous flux of solar UV photons and fast ions, e.g. galactic cosmic rays (GCRs), solar wind (SW), and solar energetic particles (SEPs), that modify the physical and chemical properties of surface materials, thus challenging the survival of organic compounds. With this in mind, the aim of this work is to estimate the lifetime of organic compounds on the Moon’s surface under processing by energetic particles. We performed laboratory experiments to measure the destruction cross section of selected organic compounds, namely methane (CH4), formamide (NH2CHO), and an organic refractory residue, under simulated Moon conditions. Volatile species were deposited at low temperature (17 - 18 K) and irradiated with energetic ions (200 keV) in an ultra-high vacuum chamber. The organic refractory residue was produced after warming up of a CO:CH4 ice mixture irradiated with 200 keV H+ at 18 K. All the samples were analyzed in situ by infrared transmission spectroscopy. We found that destruction cross sections are strongly affected (up to one order of magnitude) by the dilution of a given organic in an inert matrix. Among the selected samples, organic refractory residues are the most resistant to radiation. We estimated the lifetime of organic compounds on the surface of the Moon by calculating the dose rate due to GCRs and SEPs at the Moon’s orbit and by using the experimental cross section values. Taking into account impact gardening, we also estimated the fraction of surviving organic material as a function of depth. Our results are compatible with the detection of CH4 in the LCROSS eject plume originating from layers deeper than about 0.7 m at the Moon’s South Pole and with the identification of complex organic material in lunar samples collected by Apollo 17 mission. Godkänd;2024;NivÃ¥ 0;2024-04-22 (hanlid); Funder: PRIN-INAF 2016 TheCradle of Life - ... Article in Journal/Newspaper South pole Luleå University of Technology Publications (DiVA) Icarus 415 116077 |
institution |
Open Polar |
collection |
Luleå University of Technology Publications (DiVA) |
op_collection_id |
ftluleatu |
language |
English |
topic |
Astrobiology Astrochemistry Ice spectroscopy Laboratory astrophysics Lunar surface Astronomy Astrophysics and Cosmology Astronomi astrofysik och kosmologi |
spellingShingle |
Astrobiology Astrochemistry Ice spectroscopy Laboratory astrophysics Lunar surface Astronomy Astrophysics and Cosmology Astronomi astrofysik och kosmologi Dalla Pria, Gaia Lucrezia Sohier, O. Scirè, C. Urso, R. G. Baratta, G. A. Palumbo, M. E. Experimental study on the radiation-induced destruction of organic compounds on the surface of the Moon |
topic_facet |
Astrobiology Astrochemistry Ice spectroscopy Laboratory astrophysics Lunar surface Astronomy Astrophysics and Cosmology Astronomi astrofysik och kosmologi |
description |
Volatile organic molecules and a complex organic refractory material were detected on the Moon and on lunar samples. The Moon’s surface is exposed to a continuous flux of solar UV photons and fast ions, e.g. galactic cosmic rays (GCRs), solar wind (SW), and solar energetic particles (SEPs), that modify the physical and chemical properties of surface materials, thus challenging the survival of organic compounds. With this in mind, the aim of this work is to estimate the lifetime of organic compounds on the Moon’s surface under processing by energetic particles. We performed laboratory experiments to measure the destruction cross section of selected organic compounds, namely methane (CH4), formamide (NH2CHO), and an organic refractory residue, under simulated Moon conditions. Volatile species were deposited at low temperature (17 - 18 K) and irradiated with energetic ions (200 keV) in an ultra-high vacuum chamber. The organic refractory residue was produced after warming up of a CO:CH4 ice mixture irradiated with 200 keV H+ at 18 K. All the samples were analyzed in situ by infrared transmission spectroscopy. We found that destruction cross sections are strongly affected (up to one order of magnitude) by the dilution of a given organic in an inert matrix. Among the selected samples, organic refractory residues are the most resistant to radiation. We estimated the lifetime of organic compounds on the surface of the Moon by calculating the dose rate due to GCRs and SEPs at the Moon’s orbit and by using the experimental cross section values. Taking into account impact gardening, we also estimated the fraction of surviving organic material as a function of depth. Our results are compatible with the detection of CH4 in the LCROSS eject plume originating from layers deeper than about 0.7 m at the Moon’s South Pole and with the identification of complex organic material in lunar samples collected by Apollo 17 mission. Godkänd;2024;Nivå 0;2024-04-22 (hanlid); Funder: PRIN-INAF 2016 TheCradle of Life - ... |
format |
Article in Journal/Newspaper |
author |
Dalla Pria, Gaia Lucrezia Sohier, O. Scirè, C. Urso, R. G. Baratta, G. A. Palumbo, M. E. |
author_facet |
Dalla Pria, Gaia Lucrezia Sohier, O. Scirè, C. Urso, R. G. Baratta, G. A. Palumbo, M. E. |
author_sort |
Dalla Pria, Gaia Lucrezia |
title |
Experimental study on the radiation-induced destruction of organic compounds on the surface of the Moon |
title_short |
Experimental study on the radiation-induced destruction of organic compounds on the surface of the Moon |
title_full |
Experimental study on the radiation-induced destruction of organic compounds on the surface of the Moon |
title_fullStr |
Experimental study on the radiation-induced destruction of organic compounds on the surface of the Moon |
title_full_unstemmed |
Experimental study on the radiation-induced destruction of organic compounds on the surface of the Moon |
title_sort |
experimental study on the radiation-induced destruction of organic compounds on the surface of the moon |
publisher |
Luleå tekniska universitet |
publishDate |
2024 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-105195 https://doi.org/10.1016/j.icarus.2024.116077 |
genre |
South pole |
genre_facet |
South pole |
op_relation |
Icarus, 0019-1035, 2024, 415, http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-105195 doi:10.1016/j.icarus.2024.116077 Scopus 2-s2.0-85190112480 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1016/j.icarus.2024.116077 |
container_title |
Icarus |
container_volume |
415 |
container_start_page |
116077 |
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