Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
47,037
result(s) for
"meteorites"
Sort by:
I see falling stars
\"Young children are naturally curious about the world around them. I See Falling Stars offers answers to their most compelling questions about meteors. Age-appropriate explanations and appealing photos encourage readers to continue their quest for knowledge. Additional text features and search tools, including a glossary and an index, help students locate information and learn new words.\"-- Provided by publisher.
Book
Shooting stars
Shooting stars are bright streaks of light, but there's more to them than meets the eye! Simple text introduces readers to the science behind shooting stars. This includes what a shooting star is really made of, how they are able to shine so bright, and when readers are most likely to see them.
Book
Phosphate minerals in the H group of ordinary chondrites, and fluid activity recorded by apatite heterogeneity in the Zag H3-6 regolith breccia
Phosphate minerals in ordinary chondrites provide a record of fluids that were present during metamorphic heating of the chondrite parent asteroids. We have carried out a petrographic study of the phosphate minerals, merrillite and apatite, in metamorphosed H group ordinary chondrites of petrologic type 4-6, to understand development of phosphate minerals and associated fluid evolution during metamorphism. In unbrecciated chondrites, apatite is Cl rich and shows textural evolution from fine-grained apatite-merrillite assemblages in type 4 toward larger, uniform grains in type 6. The Cl/F ratio in apatite shows a similar degree of heterogeneity in all petrologic types, and no systematic change in compositions with metamorphic grade, which suggests that compositions in each meteorite are dictated by localized conditions, possibly because of a limited fluid/rock ratio. The development of phosphate minerals in H chondrites is similar to that of L and LL chondrites, despite the fact that feldspar equilibration resulting from albitization is complete in H4 chondrites but not in L4 or LL4 chondrites. This suggests that albitization took place during an earlier period of the metamorphic history than that recorded by preserved apatite compositions, and chemical equilibrium was not achieved throughout the H chondrite parent body or bodies during the late stages of metamorphism. A relict igneous clast in the H5 chondrite, Oro Grande has apatite rims on relict phenocrysts of (possibly) diopside that have equilibrated with the host chondrite. Apatite in the Zag H3-6 regolith breccia records a complex fluid history, which is likely related to the presence of halite in this meteorite. The porous dark H4 matrix of Zag, where halite is observed, has a high apatite/merrillite ratio, and apatite is extremely Cl rich. One light H6 clast contains similarly Cl-rich apatite. In a second light H6 clast, apatite compositions are very heterogeneous and more F-rich. Apatites in both H4 matrix and H6 clasts have very low H2O contents. Heterogeneous apatite compositions in Zag record multiple stages of regolith processing and shock at the surface of the H chondrite parent body, and apatite records either the passage of fluids of variable compositions resulting from different impact-related processes, or the passage of a single fluid whose composition evolved as it interacted with the chondrite regolith. Unraveling the history of apatite can potentially help to interpret the internal structure of chondrite parent bodies, with implications for physical and mechanical properties of chondritic asteroids. The behavior of halogens recorded by apatite is important for understanding the behavior of volatile elements in general: if impact-melt materials close to the surface of a chondritic asteroid are readily degassed, the volatile inventories of terrestrial planets could be considerably more depleted than the CI carbonaceous chondrite abundances that are commonly assumed.
Journal Article
Meteorites : the story of our solar system
\"A fascinating and authoritative introduction to the science of meteorites, written by leading experts in the field. Meteorites are rocks from space that have fallen to the Earth's surface. Once considered bad omens, they are now recognized for giving us a unique insight into the nature of the material that was present when our solar system formed. In Meteorites, experts from the Natural History Museum in London, England, provide a compelling and up-to-date introduction to these otherworldly objects. This fully illustrated guide reveals: What meteorites are; where meteorites come from; what type of celestial bodie s they come from; and information on key meteorite falls. In clear, jargon-free language, the authors explain how meteorites provide us with invaluable information about planets beyond Earth-- both within our solar system and around other stars. With its combination of color photographs, diagrams and maps, Meteorites is the ultimate reference to these mysterious objects from space\"-- Provided by publisher.
Book
Chenmingite, FeCr2O4 in the CaFe2O4-type structure, a shock-induced, high-pressure mineral in the Tissint Martian meteorite
Chenmingite (FeCr2O4; IMA 2017-036) is a high-pressure mineral, occurring as micrometer- to submicrometer-sized lamellae within precursor chromite grains along with xieite and Fe,Cr-rich ulvospinel next to shock-induced melt pockets, from the Tissint martian meteorite. The composition of type chenmingite by electron probe analysis shows an empirical formula of (Fe2+0.75Mg0.23Mn0.02) (Cr1.60Al0.29Fe3+0.06Fe2+0.04Ti0.02)Σ2.01O4. The general and end-member formulas are (Fe,Mg)(Cr,Al)2O4 and FeCr2O4. Synchrotron X-ray diffraction reveals that chenmingite has an orthorhombic Pnma CaFe2O4-type (CF) structure with unit-cell dimensions: a=9.715(6) Å, b=2.87(1) Å, c=9.49(7) Å, V=264.6(4) Å3, and Z=4. Both chenmingite and xieite formed by solid-state transformation of precursor chromite under high pressure and high temperature during the Tissint impact event on Mars. The xieite regions are always in contact with melt pockets, whereas chenmingite lamellae only occur within chromite, a few micrometers away from the melt pockets. This arrangement suggests that chenmingite formed under similar pressures as xieite but at lower temperatures, in agreement with experimental studies.
Journal Article
Cosmic debris : what it is and what we can do about it
This book examines the mysterious and the well-studied debris in Earth's crowded neighborhood. From orbiting comets to the workings of the Asteroid Belt, and from meteor showers to our home-grown network of orbiting satellites, the full diversity of space objects and the debris they create is explored. Powell also discusses some of the current research techniques used to find potentially harmful rogue elements, with an emphasis on keeping watch for any objects that may intersect Earth's orbit. Such bodies also impact other worlds, and much has been learned from observing these encounters. The information in this book is intended to foster thought about the universe in which we live, but without overloading its readers with numbers and lecture-room analysis. Like a good thriller, it allows its readers to pace themselves with the story and, by the end, encourages them to draw their own conclusions. -- Provided by publisher.
Book
Trace element inventory of meteoritic Ca-phosphates
Most extraterrestrial samples feature the two accessory Ca-phosphates (apatite-group minerals and merrillite), which are important carrier phases of the rare earth elements (REE). The trace-element concentrations (REE, Sc, Ti, V, Cr, Mn, Co, As, Rb, Sr, Y, Zr, Nb, Ba, Hf, Ta, Pb, Th, and U) of selected grains were analyzed by LA-ICP-MS and/or SIMS (REE only). This systematic investigation includes 99 apatite and 149 merrillite analyses from meteorites deriving from various asteroidal bodies including 1 carbonaceous chondrite, 8 ordinary chondrites, 3 acapulcoites, 1 winonaite, 2 eucrites, 5 shergottites, 1 ureilitic trachyandesite, 2 mesosiderites, and 1 silicate-bearing IAB iron meteorite.Although Ca-phosphates predominantly form in metamorphic and/or metasomatic reactions, some are of igneous origin. As late-stage phases that often incorporate the vast majority of their host's bulk REE budget, the investigated Ca-phosphates have REE enrichments of up to two orders of magnitude compared to the host rock's bulk concentrations. Within a single sample, each phosphate species displays a uniform REE-pattern, and variations are mainly restricted to their enrichment, therefore indicating similar formation conditions. Exceptions are brecciated samples, i.e., the Adzhi-Bogdo (LL3-6) ordinary chondrite. Despite this uniformity within single samples, distinct meteorite groups do not necessarily have unique REE-patterns. Four basic shapes dominate the REE patterns of meteoritic Ca-phosphates: (1) flat patterns, smoothly decreasing from La-Lu with prominent negative Eu anomalies (acapulcoites, eucrites, apatite from the winonaite and the ureilitic trachyandesite, merrillite from ordinary chondrites); (2) unfractionated patterns, with only minor or no anomalies (mesosiderites, enriched shergottites, IAB-iron meteorite); (3) LREE-enriched patterns, with either positive or slightly negative Eu anomalies (chondritic apatite); and (4) strongly LREE-depleted patterns, with negative Eu anomalies (depleted shergottites). The patterns do not correlate with the grade of metamorphism (petrologic type), specific adjacent mineral assemblages or with Ca-phosphate grain size. Neither the proportions of different REE, nor particular REE patterns themselves are universally correlated to a specific formation mechanism yet Eu (i.e., magnitude of the Eu anomaly) is a sensitive indicator to evaluate the timing of plagioclase and phosphate crystallization. Based on our data, U and Th abundances in apatite increase (almost linearly) with the grade of metamorphism, as well as with the differentiation of their host rock.
Journal Article