Effect of Internal Structure on the Formation of Binary Near-Earth Asteroids

内部结构对双近地小行星形成的影响

• 批准号: 1009579
• 负责人: Derek Richardson
• 金额: $ 26.73万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-15 至 2014-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1009579&HistoricalAwards=false
• 关键词: Effect; Internal; Structure; Formation; Binary

This project is a study of the effect of internal structure on the origin and evolution of binary near-Earth asteroids (NEAs). Previous NSF-supported work has shown that tidal disruption alone cannot account for the high population fraction of binary NEAs. However, the YORP thermal effect can, and also explains the critical rotation, diamond shape, and raised equatorial ridge of the best-studied binary NEA. YORP can also explain the provenance of small inner Main Belt asteroid binaries, which have not experienced tidal disruptions. Bearing in mind preliminary results on how weak cohesion affects disruption outcome, the new work includes 1) a systematic study of the effect of particle size distribution, particle shape, and simulation resolution on tidal and YORP-style rotational disruption; 2) development and deployment of a weak cohesion model; and 3) maintenance and dissemination of a database of binary asteroid properties. The team's unique high-performance simulation tools have already been responsible for important advances in the study of binary NEA formation, and this study will establish the relative importance of rubblized structure, weak cohesion, and contact binarity, on the provenance of binary asteroids. In light of rapidly improving observations and new data from recent and forthcoming spacecraft missions, this theoretical research is an important part of our understanding of the nature and evolution of small bodies in the solar system.Results from this research bear on the internal structure of NEAs, with implications both for sample return missions and for hazard mitigation strategies. The work will be the bulk of a graduate student thesis, will involve undergraduates, and will update a public repository of observed binary small bodies. This research will also strengthen international ties between the University of Maryland and l'Observatoire de la Côte d'Azur in Nice, France.

该项目研究内部结构对双近地小行星起源和演变的影响。 以前NSF支持的工作表明，潮汐破坏本身不能解释双NEAs的高人口比例。 然而，YORP的热效应可以，也解释了临界旋转，钻石形状，以及研究得最好的双星NEA的赤道脊。 YORP还可以解释小的主带内小行星双星的起源，它们没有经历过潮汐干扰。 考虑到弱凝聚力如何影响破坏结果的初步结果，新的工作包括：1）系统研究颗粒大小分布，颗粒形状和模拟分辨率对潮汐和YORP型旋转破坏的影响; 2）开发和部署弱凝聚力模型; 3）维护和传播二元小行星属性数据库。 该团队独特的高性能模拟工具已经在研究近地小行星双星形成方面取得了重要进展，这项研究将确定碎石化结构，弱凝聚力和接触双星对双星小行星起源的相对重要性。 鉴于观测工作的迅速改进以及最近和即将进行的航天器飞行任务提供的新数据，这一理论研究是我们了解太阳系小天体性质和演变的一个重要部分，研究结果对近地小行星的内部结构有影响，对取样返回飞行任务和减轻灾害战略都有影响。 这项工作将是一个研究生论文的大部分，将涉及本科生，并将更新观测到的二进制小机构的公共存储库。 这项研究还将加强马里兰州大学和法国尼斯蓝色海岸天文台之间的国际联系。