Interstellar material in meteorites: implications for the origin and evolution of the solar nebula.
Abstract
Several isotopic anomalies, unexplained by known nuclear or nonnuclear processes, within the solar system have been attributed to the preservation of presolar variations. The largest of these (in number of atoms) is an O-16 excess (up to 5%) in 'high-temperature condensate' minerals in primitive meteorites. Some of these same minerals have an excess of Mg-26, probably a decay product of Al-26, that could have been a major source of heat for melting and metamorphosing planetesimals. Excesses of Ne-22 and of isotopes of Xe found in carbonaceous chondrites may have origins in presolar solid particles. The large variation in the isotopic abundances of nitrogen and carbon in meteorites may also represent isotopic heterogeneity in the solar nebula. Most of these 'isotopically anomalous' elements are found to be highly concentrated in minute phases within the meteorites, rather than being uniformly distributed. The identification and characterization of these carriers of presolar materials constitutes the principal thrust of current research in this area.
- Publication:
-
IAU Colloq. 39: Comets, Asteroids, Meteorites: Interrelations, Evolution and Origins
- Pub Date:
- 1977
- Bibcode:
- 1977cami.coll..335C
- Keywords:
-
- Interstellar Matter;
- Meteoritic Composition;
- Solar System;
- Carbon Isotopes;
- Isotope Effect;
- Krypton Isotopes;
- Magnesium;
- Mercury Isotopes;
- Neon Isotopes;
- Nitrogen Isotopes;
- Nuclear Fusion;
- Osmium Isotopes;
- Oxygen Isotopes;
- Xenon Isotopes;
- Lunar and Planetary Exploration;
- Chemical Composition:Meteorites;
- Evolution:Solar Nebula