Related papers: Presolar stardust in asteroid Ryugu

The vast majority (>=90%) of presolar SiC grains identified in primitive meteorites are relics of ancient asymptotic giant branch (AGB) stars, whose ejecta were incorporated into the Solar System during its formation. Detailed…

We report Mo isotopic data of 27 new presolar SiC grains, including 12 14N-rich AB (14N/15N>440, AB2) and 15 mainstream (MS) grains, and their correlated Sr and Ba isotope ratios when available. Direct comparison of the data for the MS…

The analysis of biorelevant molecules in returned mission samples such as from the carbonaceous asteroid (162173) Ryugu is key to unravelling the role of extraterrestrial organics in the evolution of life. Coordinated analyses using…

Neutron-rich isotopes with masses near that of iron are produced in type Ia and II supernovae. Traces of such nucleosynthesis are found in primitive meteorites in the form of variations in the isotopic abundance of 54Cr, the most…

C and O isotopic ratios are reported for a sample of 46 Mira and SRa-type variable AGB stars. Vibration-rotation 1st and 2nd overtone CO lines in 1.5 to 2.5 $\mu$m spectra were measured to derive isotopic ratios for 12C/13C, 16O/17O, and…

This work presents a large consistent study of molybdenum (Mo) and ruthenium (Ru) abundances in the Milky Way. These two elements are important nucleosynthetic diagnostics. In our sample of 71 Galactic metal-poor field stars, we detect Ru…

Recent space missions have provided information on the physical and chemical properties of interstellar grains such as the ratio $\beta$ of radiation pressure to gravity acting on the grains in addition to the composition, structure, and…

We calculate and discuss the chemical evolution of the isotopic silicon abundances in the interstellar medium at distances and times appropriate to the birth of the solar system. This has several objectives, some of which are related to…

Isotopic ratios of C, N, Si, and trace heavy elements in presolar SiC grains from meteorites provide crucial constraints to nucleosynthesis. A long-debated issue is the origin of the so-called A+B grains, as for them no stellar progenitor…

The JAXA Hayabusa-2 mission was approved in 2010 and launched on December 3, 2014. The spacecraft will arrive at the near-Earth asteroid 162173 Ryugu in 2018 where it will perform a survey, land and obtain surface material, then depart in…

We present new multielement NanoSIMS isotopic measurements (C, N, Si, Mg-Al, Ti, and Ni) for four putative nova SiC grains and 79 AB SiC grains from the Murchison meteorite to reassess their stellar origins. High-resolution imaging and a…

China plans to return samples from the near-Earth asteroid (469219) Kamo'oalewa, which we previously identified as an LL-chondrite-compositional, highly space-weathered object with fine-grained regolith. In this study, we developed 10 mL of…

Because of relatively high surface temperatures and quick evolution of orbital parameters of near-Earth asteroids (NEAs) of primitive types, the possibility of retention of icy materials (predominately H2O ice) remains in question. Yet,…

Knowledge about the age of presolar grains provides important insights into Galactic chemical evolution and the dynamics of grain formation and destruction processes in the Galaxy. Determination from the abundance of cosmic ray interaction…

Laboratory analyses on fine-grained diamond residues from primitive meteorites have shown that nano-diamonds represent the most abundant form of presolar dust preserved in meteoritic samples. The presolar diamonds carry isotopic anomalies…

Using the multi-band imager MapCam onboard the OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer) spacecraft, we identified 77 instances of proposed exogenic materials distributed globally…

Carbonaceous chondrites are among the most important meteorite types and have played a vital role in deciphering the origin and evolution of our solar system. They have been linked to low-albedo C-type asteroids, but due to subdued…

We report on the results of NanoSIMS isotope imaging of low-density supernova graphite grains from the Orgueil meteorite. 70 nm thick microtomed sections of three supernova graphite grains were deposited on Si wafers and isotopically imaged…

In situ observations of small asteroids show that surfaces covered by boulders and coarse terrain are frequent on such bodies. Regolith grain sizes have distributions on approximately mm and cm scales, and the behavior of such large grains…

Mainstream presolar SiC grains from primitive meteorites show a clear s-process signature in the isotopic composition of heavy trace elements. These grains most likely condensed in the winds of a variety of AGB stars. However, the non-solar…