Hypervelocity impacts as a source of deceiving surface signatures on iron-rich asteroids
Hypervelocity impacts as a source of deceiving surface signatures on iron-rich asteroids
复制标题
超高速撞击是富铁小行星表面特征的欺骗性来源
作者：
G. Libourel;A. Nakamura;P. Beck;S. Potin;C. Ganino;S. Jacomet;R. Ogawa;S. Hasegawa;P. Michel
超高速撞击产生了意想不到的特征，例如富含金属的小行星表面有玻璃涂层和水合特征。一些论点指出，与光谱观测相比，富含金属的小行星所占比例更大，因为它们是分化天体碰撞破坏的残留物。我们的实验表明，这种明显的缺陷可能是在典型的小行星撞击速度下，水合或干燥的弹丸撞击时产生的硅酸盐熔体在金属表面上覆盖的结果。对撞击后的钢铁陨石目标进行的光谱分析显示，光学特征得到了深刻的修改。此外，水合弹丸还具有3-μm的吸收水合特性。因此，这一特性与金属表面一致，不需要异常的低速撞击。除非将雷达测量系统化，否则地面光谱观测在识别富铁天体方面可能具有欺骗性。美国宇航局的普赛克任务与普赛克的会合将提供一个独特的机会，既可以测量风化层和玻璃涂层表面的相对丰度，也可以显著增加我们对富含金属的小行星撞击过程和特征的理解。
Hypervelocity impacts produce unexpected signatures such as glassy coating and hydrated features on metal-rich asteroid surfaces. Several arguments point to a larger proportion of metal-rich asteroids than that derived from spectral observations, as remnants of collisional disruptions of differentiated bodies. We show experimentally that this apparent deficit may result from the coating of metallic surfaces by silicate melts produced during impacts of hydrated or dry projectiles at typical asteroid impact speeds. Spectral analysis of steel and iron meteorite targets after impact shows a profoundly modified optical signature. Furthermore, hydrated projectiles leave a 3-μm absorption hydration feature. This feature is thus consistent with a metallic surface and does not require an unusual low-speed impact. Unless systematizing radar measurements, ground-based spectral observations can be deceptive in identifying iron-rich bodies. The NASA Psyche mission rendezvous with Psyche will offer the unique opportunity both to measure the relative abundances of regolith and glassy coated surfaces and to substantially increase our understanding of impact processes and signatures on a metal-rich asteroid.
影响因子：
56.9
作者：
Kruijer, T. S.;Touboul, M.;Kleine, T.
通讯作者：
Kleine, T.
全球范围的影响
DOI：
10.48550/arxiv.1504.02389
发表时间：
2015
期刊：
--
影响因子：
--
作者：
Asphaug E
通讯作者：
Asphaug E