کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8134256 1523484 2018 20 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Escape and fractionation of volatiles and noble gases from Mars-sized planetary embryos and growing protoplanets
ترجمه فارسی عنوان
فرار و تقسیم بندی فرار و گازهای نجیب از جنین های سیاره ای مریخ و پروتوپلاکت های در حال رشد
کلمات کلیدی
تکامل اتمسفر، تابش خورشیدی، شکل گیری سیاره،
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات علوم فضا و نجوم
چکیده انگلیسی
Furthermore, we study the influence on protoplanetary evolution, exemplified by Venus. In particular, we investigate different early evolution scenarios and constrain realistic cases by comparing modeled noble gas isotope ratios with present observations. Isotope ratios of Ne and Ar can be reproduced, starting from solar values, under hydrodynamic escape conditions. Solutions can be found for different solar EUV histories, as well as assumptions about the initial atmosphere, assuming either a pure steam atmosphere or a mixture with accreted hydrogen from the protoplanetary nebula. Our results generally favor an early accretion scenario with a small amount of residual hydrogen from the protoplanetary nebula and a low-activity Sun, because in other cases too much CO2 is lost during evolution, which is inconsistent with Venus' present atmosphere. Important issues are likely the time at which the initial steam atmosphere is outgassed and/or the amount of CO2 which may still be delivered at later evolutionary stages. A late accretion scenario can only reproduce present isotope ratios for a highly active young Sun, but then unrealistically massive steam atmospheres (few kbar) would be required.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Icarus - Volume 307, June 2018, Pages 327-346
نویسندگان
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