Isotopic and Micro-Raman investigation of Interplanetary Dust Particles Collected during 2003 Earth passage through Comet Grigg-Skjellerup Dust Stream

We report microscale H and N isotopic and Raman spectral data for IDPs collected in April 2003. The samples show extreme D and 15N enrichments carried by very primitive organic matter. A high abundance of D anomalies might indicate a cometary origin

Remarkably high abundance of presolar grains in interplanetary dust particles collected from the comet Grigg-Skjellerup dust stream

Isotopic studies of IDPs collected from the comet Grigg-Skjellerup dust stream reveal extremely high abundances of presolar grains in two of four IDPs. These abundances exceed those of any other extraterrestrial material analyzed and support a cometary origin for these IDPs

Galactic age estimates from O-rich stardust in meteorites

The 16O/17O and 16O/18O ratios of refractory oxide grains extracted from primitive meteorites suggest that they originated in low-mass red giant stars prior to the formation of the Solar System 4.6×109 years ago. Detailed comparison of the isotopic compositions of the grains with models of stellar evolution and galactic chemical evolution imply that the age of the Galaxy is 14.4 Gyr with a statistical error of ±1.3 Gyr. Systematic uncertainties are of order several Gyr, however, and are primarily due to inadequacies in present theoretical modeling

Correlated analytical studies of organic material from the Tagish Lake carbonaceous chondrite

We report on correlated studies of organic material using SIMS, FIB-SEM, and TEM

Extensive microscale N isotopic heterogeneity in chondritic organic matter

Introduction: H and N isotopic anomalies (mainly excesses of D and 15N) in organic matter from primitive meteorites and IDPs suggest preservation of presolar molecular cloud material [1-3]. However, there have been very few spatially correlated H and N studies for either chondrites or IDPs [4, 5]. We report C and N isotopic imaging data for organic matter from four meteorites and three IDPs. D/H imaging data for many of the same samples are presented in [6, 7] and bulk organic isotope data in [8]

Extreme H isotopic anomalies in chondritic organic matter

Extract from introduction: We have conducted ionprobe (IMS6f and NanoSIMS) imaging studies of various samples for H, D, C, 14N and 15N. These will ultimately be correlated with micro-analytic techniques such as FIB/TEM or STXM/XANES. We analyzed matrix fragments from Bells (CM2), Al Rais (CR2) and Tagish Lake (unique) [2], high purity insoluble organic matter (IOM) [3] extracted from EET92042 (“EET”, CR2), Bells, Murchison (CM2), Allende (CV3), Krymka (LL3.1) and, for comparison, 3 IDPs

Secondary ion mass spectrometry and x-ray absorption near-edge structure spectroscopy of isotopically anomalous organic matter from CR1 chondrites GRO 95577

We located interstellar organics from a CR1 chondrite with NanoSIMS and analyzed FIB-extracted sections with XANES. D-rich material appears not associated with a functional group, whereas 15N-rich matter shows some affinity to nitrile functionality

Correlated Microscale Isotope and Scanning Transmission X-Ray Analyses of Isotopically Anomalous Organic Matter from the CR2 Chondrite EET 92042

We discuss correlated examinations of organic matter from the CR2 chondrite EET 92042, using SIMS, STXM and other methods. We found a large, isotopically highly anomalous region of probable presolar origin that is C- and 13C-poor and 15N-rich