期刊
ICARUS
卷 211, 期 2, 页码 986-992出版社
ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1016/j.icarus.2010.11.005
关键词
Impact processes; Comet Wild-2; Comets, Dust
资金
- Japan Ministry of Education, Culture, Sports, Science and Technology [19104012]
- Grants-in-Aid for Scientific Research [19104012] Funding Source: KAKEN
A large number of cometary dust particles were captured with low-density silica aerogels by NASA's Stardust Mission. Knowledge of the details of the capture mechanism of hypervelocity particles in silica aerogel is needed in order to correctly derive the original particle features from impact tracks. However, the mechanism has not been fully understood yet. We shot hard spherical projectiles of several different materials into silica aerogel of density 60 mg cm(-3) and observed their penetration processes using an image converter or a high-speed video camera. In order to observe the deceleration of projectiles clearly, we carried out impact experiments at two velocity ranges; similar to 4 km s(-1) and similar to 200 m s(-1). From the movies we took, it was indicated that the projectiles were decelerated by hydrodynamic force which was proportional to v(2) (v. projectile velocity) during the faster penetration process (similar to 4 km s(-1)) and they were merely overcoming the aerogel crushing strength during the slower penetration process (similar to 200 m s(-1)). We applied these deceleration mechanisms for whole capture process to calculate the track length. Our model well explains the track length in the experimental data set by Burchell et al. (Burchell, M.J., Creighton, J.A., Cole, M.J., Mann, J., Kearsley, A.T. [2001]. Meteorit. Planet. Sci. 36, 209-221). (C) 2010 Elsevier Inc. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据