Abstract
Anhydrous interplanetary dust particles (IDPs), which are the most mineralogically primitive extraterrestrial materials available for laboratory analysis, contain several percent organic matter. The high O:C and N:C ratios suggest the organic matter in the anhydrous IDPs is significantly less altered by thermal processing than the organic matter in meteorites. X-ray Absorption Near-Edge Structure (XANES) spectroscopy and infrared spectroscopy demonstrate the presence of C=C, most likely as C-rings, C=O, and aliphatic C-H2 and C-H3 in all the IDPs examined. A D-rich spot, containing material that is believed to have formed in a cold molecular cloud, has C-XANES and infrared spectra very similar to the organic matter in the anhydrous IDPs, possibly indicating a common formation mechanism. However the primitive organic matter in the IDPs differs from the interstellar/circumstellar organic matter characterized by astronomical infrared spectroscopy in the relative strengths of the asymmetric aliphatic C-H2 and C-H3 absorptions, with the IDP organic having a longer mean chain length. If both types of organic matter originated by the same process, this may indicate the interstellar organic matter has experienced more severe radiation processing than the organic matter in the primitive IDPs.
Original language | English (US) |
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Title of host publication | Organic Matter in Space |
Pages | 267-275 |
Number of pages | 9 |
Edition | S251 |
DOIs | |
State | Published - 2008 |
Publication series
Name | Proceedings of the International Astronomical Union |
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Number | S251 |
Volume | 4 |
ISSN (Print) | 1743-9213 |
ISSN (Electronic) | 1743-9221 |
Funding
This work was supported by a NASA Exobiology grant. The measurements were performed on beamlines U10B and X1A of the National Synchrotron Light Source at Brookhaven National Laboratory.
Keywords
- Astrobiology
- Astrochemistry
- Infrared: general
ASJC Scopus subject areas
- Medicine (miscellaneous)
- Astronomy and Astrophysics
- Nutrition and Dietetics
- Public Health, Environmental and Occupational Health
- Space and Planetary Science