کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8134466 | 1523487 | 2018 | 44 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Equatorial cavities on asteroids, an evidence of fission events
ترجمه فارسی عنوان
حفره های استوایی سیارک ها، شواهدی از وقوع شکافت است
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کلمات کلیدی
سیارک، شکافتن گرانش موثر، ساختار، انسجام،
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
علوم فضا و نجوم
چکیده انگلیسی
This paper investigates the equatorial cavities found on asteroids 2008 EV5 and 2000 DP107 Alpha. As the likelihood of these cavities being impact craters is demonstrated to be low, the paper presents a fission mechanism that explains their existence as a scar of past fission events. The dynamical environment of “top-shaped” asteroids is such that, at high spin rates, an identifiable equatorial region enters into tension before the rest of the body. We propose hypothetical past shapes for 2008 EV5 and 2000 DP107, with mass added within the cavity to recreate a smoother equatorial ridge. The dynamical environment of these hypothetical parent bodies reveal that this modified region is indeed set in tension when spin is increased. The fission process requires tensile strength at the interface between the ejecta and the remaining body, at the moment of fission, between 0 and 2⯠Pa for 2008 EV5 and between 0 and 15⯠Pa for 2000 DP107, depending on the precise fission scenario considered. Going back to the spin-up deformation phase of the asteroids, the paper examines how kinetic sieving can form predominantly rocky equators, whose tensile strength could be much lower than that of the rest of the body. This process could explain the low cohesion values implied for this fission mechanism.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Icarus - Volume 304, April 2018, Pages 192-208
Journal: Icarus - Volume 304, April 2018, Pages 192-208
نویسندگان
Simon Tardivel, Paul Sánchez, Daniel J. Scheeres,