کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8138858 | 1523561 | 2014 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Scheila's scar: Direct evidence of impact surface alteration on a primitive asteroid
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
علوم فضا و نجوم
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چکیده انگلیسی
Asteroid (596) Scheila was the first object for which the immediate aftermath of an inter-asteroidal collision was observed. In December 2010, the 113Â km-sized asteroid was impacted by a smaller asteroid of less than 100Â m in diameter. The scale of the impactor was established by observations of fading ejecta plumes. Comparison of the lightcurves obtained before and after the impact allowed us to assess how much of Scheila's surface was altered. Cratering physics based on the impactor size suggests that the size of the affected area is larger than expected, (effective radii of 3.5-10Â km depending on the change in the albedo of the surface). Similar but more localized albedo changes have been observed on Vesta and the martian moons, but are not understood. Empirical laws describing ejecta blankets however indicate that at distances between 3.5 and 10Â km from the crater, Scheila's surface would be covered by a thin layer 2Â mm to 2Â cm thick. This dusting, possibly mixed with bright impactor material may be enough to explain to observed brightness increase. Our results show that sub-critical impacts may play a significant role in processing the surfaces of asteroids. The large effect of small impacts on asteroidal lightcurves complicate shape modeling.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Icarus - Volume 229, February 2014, Pages 190-195
Journal: Icarus - Volume 229, February 2014, Pages 190-195
نویسندگان
D. Bodewits, J.-B. Vincent, M.S.P. Kelley,