Radar observations and the shape of near-Earth ASTEROID 2008 EV5

被引：80

作者：

Busch, Michael W. ^{[1
]}

Ostro, Steven J. ^{[2
]}

Benner, Lance A. M. ^{[2
]}

Brozovic, Marina ^{[2
]}

Giorgini, Jon D. ^{[2
]}

Jao, Joseph S. ^{[2
]}

Scheeres, Daniel J. ^{[3
]}

Magri, Christopher ^{[4
]}

Nolan, Michael C. ^{[5
]}

Howell, Ellen S. ^{[5
]}

Taylor, Patrick A. ^{[5
]}

Margot, Jean-Luc ^{[1
,6
]}

Brisken, Walter ^{[7
]}

机构：

[1] Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA

[2] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA

[3] Univ Colorado, Dept Aerosp Engn Sci, Boulder, CO 80309 USA

[4] Univ Maine, Farmington, ME 04938 USA

[5] Arecibo Observ, Arecibo, PR 00612 USA

[6] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA

[7] Natl Radio Astron Observ, Socorro, NM 87801 USA

来源：

ICARUS | 2011年 / 212卷 / 02期

基金：

美国国家科学基金会; 美国国家航空航天局;

关键词：

Asteroids; Surfaces; Dynamics; Radar observations; YARKOVSKY; SPINS;

D O I：

10.1016/j.icarus.2011.01.013

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We observed the near-Earth ASTEROID 2008 EV5 with the Arecibo and Goldstone planetary radars and the Very Long Baseline Array during December 2008. EV5 rotates retrograde and its overall shape is a 400 +/- 50 m oblate spheroid. The most prominent surface feature is a ridge parallel to the asteroid's equator that is broken by a concavity about 150 m in diameter. Otherwise the asteroid's surface is notably smooth on decameter scales. EV5's radar and optical albedos are consistent with either rocky or stony-iron composition. The equatorial ridge is similar to structure seen on the rubble-pile near-Earth asteroid (66391) 1999 KW4 and is consistent with YORP spin-up reconfiguring the asteroid in the past. We interpret the concavity as an impact crater. Shaking during the impact and later regolith redistribution may have erased smaller features, explaining the general lack of decameter-scale surface structure. (C) 2011 Elsevier Inc. All rights reserved.

引用

页码：649 / 660

页数：12

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