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Emissivity Spectra of Meteoritic Powders mixed with Liquid Formamide (CH3NO) at Different Temperatures

Saladino, Raffaele and Maturilli, Alessandro and Helbert, Jörn and de Vera, Jean Pierre Paul and D'Amore, Mario and Ferrari, Sabrina (2013) Emissivity Spectra of Meteoritic Powders mixed with Liquid Formamide (CH3NO) at Different Temperatures. AGU 2013, 9.-13. Dez. 2013, San Francisco, Kalifornien, USA.

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Abstract

We set-up an experiment at the Planetary Emissivity Laboratory (PEL) to investigate a key aspect in the prebiotic chemistry of formamide: the surface reactivity of minerals used as catalysts. The interaction of formamide and the reaction products on mineral surface, as well as, the sequestration processes in the mineral pores, can facilitate the concentration of products allowing for possible polymerization. Three meteorites, NWA2828 (PEL ID 00000887), Al Haggounia (PEL ID 00000888), and Dhofar959 (PEL ID 00000889), were used in this experiment. All the samples were reduced in the grain size fraction < 125 µm and stored in a desiccator before measuring. Each sample was poured in one from a set of identical stainless steel cups, having 5 mm thick bottom, internal diameter 50 mm, rim thickness 2 mm, and 20 mm total height. Emissivity of the samples was measured by means of a Bruker Vertex 80V coupled to an emissivity chamber (equipped with a rotating carousel to measure several samples without breaking the vacuum), both evacuable to < 1 mbar. The dry samples were placed in the emissivity chamber, each of them having a temperature sensor in contact with the surface of the sample, reading the effective temperature of the emitting skin. The “dry” meteorites were measured in vacuum (0.8 mbar) at 70° C on the sample surface, successively liquid formamide was vaporized on the samples surface, the cup was immediately transferred in the emissivity chamber, and evacuated. Each sample was measured at 70°, 100°, 140°, and 200° C. Then each cup was cooled in vacuum and put back in the desiccator. For each sample after this thermal processing, a small amount of heated material was used to fill a cup for reflectance measurements. Since cold reflectance measurements cannot be compared with hot emissivity, those measurements have been taken to better understand the processes happening in the moisturized soil after heating. For all of the samples, when heating at 70°C we noticed in the emissivity spectra strong signatures attributable to liquid formamide. We interpret them as being originated from a column of hot vaporized formamide, lying above the sample surface. For all the samples this effect vanished already at 100°C, probably due to complete evaporation of liquid formamide that was deposited on the meteorite sample surfaces. However, all the spectra measured at 100° and 140° C show signs of the presence of formamide, that we infer from comparing them with the 70° C dry measurement of the same sample. For 2 samples out of 3, when heating at 200°C (and only there) a new feature appears at 7.08 µm. This band is very close to a similar band that liquid formamide has at 7.19 µm, and that was even present in all the spectra of wet meteorites taken at 70°C. We interpret this band shift as a possible sign of interaction of formamide with the catalyst (the meteorite powder): the CH bend responsible for that is probably strengthening.

Item URL in elib:https://elib.dlr.de/87018/
Document Type:Conference or Workshop Item (Poster)
Title:Emissivity Spectra of Meteoritic Powders mixed with Liquid Formamide (CH3NO) at Different Temperatures
Authors:
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Saladino, RaffaeleDepartment of Agrobiology and Agrochemistry, University of ViterboUNSPECIFIED
Maturilli, AlessandroAlessandro.Maturilli (at) dlr.deUNSPECIFIED
Helbert, JörnJoern.Helbert (at) dlr.dehttps://orcid.org/0000-0001-5346-9505
de Vera, Jean Pierre Pauljean-pierre.devera (at) dlr.deUNSPECIFIED
D'Amore, Mariomario.damore (at) dlr.deUNSPECIFIED
Ferrari, Sabrinasabrina.ferrari (at) dlr.deUNSPECIFIED
Date:8 December 2013
Refereed publication:No
Open Access:Yes
Gold Open Access:No
In SCOPUS:No
In ISI Web of Science:No
Status:Published
Keywords:Astoroiden, Formamide
Event Title:AGU 2013
Event Location:San Francisco, Kalifornien, USA
Event Type:international Conference
Event Dates:9.-13. Dez. 2013
Organizer:AGU
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Space
HGF - Program Themes:Space Science and Exploration
DLR - Research area:Raumfahrt
DLR - Program:R EW - Erforschung des Weltraums
DLR - Research theme (Project):R - Vorhaben BepiColombo (old)
Location: Berlin-Adlershof
Institutes and Institutions:Institute of Planetary Research > Experimentelle Planetenphysik
Deposited By: Maturilli, Alessandro
Deposited On:06 Jan 2014 08:02
Last Modified:31 Jul 2019 19:44

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