Geochemical arguments for an Earth-like Moon-forming impactor
نویسندگان
چکیده
منابع مشابه
Geochemical arguments for an Earth-like Moon-forming impactor.
Geochemical evidence suggests that the material accreted by the Earth did not change in nature during Earth's accretion, presumably because the inner protoplanetary disc had uniform isotopic composition similar to enstatite chondrites, aubrites and ungrouped achondrite NWA 5363/5400. Enstatite meteorites and the Earth were derived from the same nebular reservoir but diverged in their chemical e...
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Introduction: Major ambiguities remain in our current understanding of the geochemical evolution of the moon. That situation arises partly because (a) our geochemical and isotopic data sets for mare basalts are overly influenced by samples from the Procellarum KREEP Terrain (PKT [1]), and (b) samples of the highland crust useful for isotopic studies are limited in both quantity and quality. Fut...
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The Earth formed through accretion of planetesimals in 1–100 million years. Planetesimal impacts induce degassing, melting, and vaporization during accretion. The impact degassing, as well as the gravitational capture of the surrounding solar nebula gas, formed the proto-atmosphere on a growing Earth. The impact of heating and the blanketing effect of the proto-atmosphere resulted in the meltin...
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A graph G has surface thickness n (S-thickness n) with respect to the surface S, if G can be decomposed into n and no fewer subgraphs by making n copies of the vertex set of G and then assigning each edge of G to one of the n copies so that n graphs result; each resulting subgraph of G must be S embeddable. The chromatic number of a graph G, denoted χ(G), is simply the fewest number of colors n...
متن کاملFast accretion of the earth with a late moon-forming giant impact.
Constraints on the formation history of the Earth are critical for understanding of planet formation processes. (182)Hf-(182)W chronometry of terrestrial rocks points to accretion of Earth in approximately 30 Myr after the formation of the solar system, immediately followed by the Moon-forming giant impact (MGI). Nevertheless, some N-body simulations and (182)Hf-(182)W and (87)Rb-(87)Sr chronol...
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ژورنال
عنوان ژورنال: Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences
سال: 2014
ISSN: 1364-503X,1471-2962
DOI: 10.1098/rsta.2013.0244