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تسجيل مستخدم جديدA Pilot Search for Evidence of Extrasolar Earth-analog Plate Tectonics
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Relative to calcium, both strontium and barium are markedly enriched in Earths continental crust compared to the basaltic crusts of other differentiated rocky bodies within the solar system. Here, we both re-examine available archived Keck spectra to place upper bounds on n(Ba)/n(Ca) and revisit published results for n(Sr)/n(Ca) in two white dwarfs that have accreted rocky planetesimals. We find that at most only a small fraction of the pollution is from crustal material that has experienced the distinctive elemental enhancements induced by Earth-analog plate tectonics. In view of the intense theoretical interest in the physical structure of extrasolar rocky planets, this search should be extended to additional targets.
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Plate tectonics is a geophysical process currently unique to Earth, has an important role in regulating the Earths climate, and may be better understood by identifying rocky planets outside our solar system with tectonic activity. The key criterion f
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