RUI: Saturn's Rings

RUI：土星环

• 批准号: 0307800
• 负责人: Richard French
• 金额: $ 19.64万
• 依托单位: Wellesley College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-10-01 至 2007-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0307800&HistoricalAwards=false
• 关键词: RUI; Saturn; Rings

AST 0307800FrenchThe objective of this project is to develop a deeper understanding of the dynamics and structure of Saturn's rings, through a comprehensive investigation of dramatic variations in their apparent brightness with ring longitude. This azimuthal brightness asymmetry is generally ascribed to gravitational wakes -- clumps of ring particles attempting to accrete under their mutual gravitation, but frustrated in the attempt by Saturn.s strong tidal influence. Dr. Richard French, at Wellesley College, will compare measurements of the asymmetry from a rich set of hundreds of Hubble Space Telescope images and multiple radar images of the rings from Arecibo Observatory, with the predictions of dynamical models of gravitational wakes. The N-body simulations of the detailed structure of the rings, and the resulting gravitational wakes, show a very strong dependence on the detailed properties of the rings, such as the distribution of particle sizes, the surface mass density, and the elasticity of interparticle collisions. The strength of the resulting asymmetry also varies greatly across the rings, for reasons that are not yet completely understood. This work will quantify the newly-discovered azimuthal asymmetry in the inner B ring, for example. This project will be of general interest to planetary scientists because it combines two complementary, superb quality data sets (a decade of HST observations and several years of Arecibo radar results) with a realistic physical description of the rings. The research will address fundamental characteristics of ring dynamics, such as gravitational instabilities, as well as properties of the ring particles themselves. The observations and analysis will provide a firm foundation for Cassini mission investigation of the rings. The HST and Arecibo data will not be supplanted by Cassini observations, because they have been taken under different viewing geometries and they sample very different parts of the scattering phase function of the particles. The investigator will relate the research to the educational life of Wellesley College, an undergraduate women's college with a history of success in educating women in science. This will be accomplished by supervising honors thesis students and undergraduate summer students, and by incorporating detailed examples of their research in both introductory and advanced courses. Dr. French will continue a successful outreach program by leading several-day seminars to about 25 K-12 teachers each year on the relationship between modern planetary science and terrestrial concerns such as global climate change and the consequences of giant impacts, and he will share the ongoing research under this project with teachers and the general public at a non-technical level. This award is made under the Research at Undergraduate Institutions program at NSF.***

AST 0307800 French该项目的目标是通过全面调查土星环视亮度随环经度的剧烈变化，加深对土星环动力学和结构的了解。这种方位角亮度不对称通常归因于引力尾流-环粒子团试图在相互引力下吸积，但在土星强烈的潮汐影响下失败。 韦尔斯利学院的理查德·弗伦奇博士将比较数百张哈勃太空望远镜图像和阿雷西博天文台的多张雷达图像中的不对称测量结果，以及引力尾流动力学模型的预测。对环的详细结构的N体模拟，以及由此产生的引力尾流，显示了对环的详细性质的非常强的依赖性，例如颗粒尺寸的分布，表面质量密度和粒子间碰撞的弹性。由于尚未完全理解的原因，所产生的不对称性的强度在环之间也有很大的差异。例如，这项工作将量化新发现的内B环的方位不对称性。 该项目将引起行星科学家的普遍兴趣，因为它结合了两个互补的高质量数据集（10年的HST观测和几年的Arecibo雷达结果），并对环进行了真实的物理描述。 这项研究将解决环动力学的基本特征，如引力不稳定性，以及环粒子本身的性质。这些观测和分析将为卡西尼使命的环研究提供坚实的基础。HST和Arecibo的数据不会被卡西尼号的观测所取代，因为它们是在不同的观测几何条件下拍摄的，并且它们对粒子散射相函数的不同部分进行了采样。 调查者将把研究与韦尔斯利学院的教育生活联系起来，韦尔斯利学院是一所本科女子学院，在教育妇女从事科学方面有着成功的历史。这将通过监督荣誉论文学生和本科暑期学生，并通过将他们的研究在介绍和高级课程的详细例子来完成。弗伦奇博士将继续一个成功的推广计划，每年为大约25名K-12教师举办为期几天的研讨会，讨论现代行星科学与地球问题之间的关系，如全球气候变化和巨大撞击的后果，他亦会在非技术层面上，与教师及公众分享这项计划的研究成果。该奖项是根据NSF的本科院校研究计划颁发的。*