Isotopic analysis of cometary organic matter.
Carbon isotope ratios have been measured for CN in the coma of comet Halley and for several CHON particles emitted by Halley.  Of these, only the CHON-particle data may be reasonably related to organic matter in the cometary nucleus, but the true range of 13C/12C values in those particles is quite uncertain.  The D/H ratio in H2O in the Halley coma resembles that in Titan/Uranus.  The next decade should substantially improve our understanding of the distribution of C, H, N, and O isotopes in cometary organics.  The isotopic composition of meteoritic organic matter is better understood and can serve as a useful analog for the cometary case.
Kerridge
J F
JF
Institute of Geophysics, University of California, Los Angeles 90024-1567, USA.
D002244:Carbon / Q000032:analysis*; D002247:Carbon Isotopes; D055598:Chemical Phenomena; D002621:Chemistry; D003486:Cyanides / Q000032:analysis; D005118:Extraterrestrial Environment; D019110:Meteoroids; D009584:Nitrogen / Q000032:analysis*; D009587:Nitrogen Isotopes; D010100:Oxygen / Q000032:analysis*; D010103:Oxygen Isotopes; D016082:Solar System; D013696:Temperature
D002247:Carbon Isotopes; D003486:Cyanides; D009587:Nitrogen Isotopes; D010103:Oxygen Isotopes; D002244:Carbon; D009584:Nitrogen; D010100:Oxygen