Near-Earth Object Reconnaissance and Source Region Analysis

有了这个奖项，理查德·宾泽尔博士和他的同事们将对居住在与地球轨道相交（或接近）的轨道上的小天体的基本特征和起源有更多的了解。这些近地天体在科学上是重要的，因为它们是向地球输送陨石的最直接和最具代表性的源体。目前，近地天体的起源大多是未知的，来自主要小行星带和已灭绝的彗星。为了对新发现的近地天体进行常规侦察，位于夏威夷莫纳克亚山的美国宇航局红外望远镜设施（IRTF）承诺了多年的观测时间（在最初的两年里每月约2个晚上）。美国国家科学基金会对该项目的资助将支持这些侦察观测的获取，从而每年为80到100个近地天体提供新的光谱数据，其中所有获得的新数据将被压缩并以近乎实时的方式公开发布。在短时间内，这个新的侦察计划将超过目前近红外光谱测量的近地天体数量（约140个）。这些侦察观测的具体科学目标是：(1)尽可能地将近地天体光谱特征与主要陨石类别联系起来。(2)定量确定在太空中测量到的近地天体种群类别与地球上的陨星种群类别之间的相对一致性（或缺乏一致性）。(3)尽可能确定特定类近地天体的特定主带源区，进而阐明特定陨石类型的太阳系起源环节。(4)表征类彗星轨道上近地天体的性质，以阐明小行星与彗星之间的联系，从而约束近地天体的彗星源比例。(5)测量在推进要求为7km /sec的可达轨道上运行的近地天体的光谱特性，使任务规划能够以科学标准（对目标特性的基本知识）为依据，而不是简单的动力学要求。(6)单独评估潜在危险小行星（PHA）亚群的组成特性，以阐明这些最接近的物体与更广泛的近地天体群相比所造成的相对危害的任何差异。Binzel博士和他的团队为这个项目带来了丰富的光谱经验，在前三年资助期的头两年里，他们发表了10多篇论文，进行了约140次近地天体观测，在小行星研究方面也有更长的记录。为了社会的长远利益，我们必须了解近地天体的数量，以便评估它们的影响危害和利用空间自然资源的潜力。将近地天体的天文测量与陨石的实验室测量联系起来，在不同的科学学科之间提供了广泛的联系。确定与陨石类别相关的近地天体的来源区域，将大量关于太阳系形成条件的实验室陨石数据锚定在不同的位置，作为形成我们太阳系内外行星的重要边界条件。近地天体的接近性使其成为航天器探索最容易到达的目的地，使其侦察对美国和国际空间探索规划至关重要，包括可能的未来人类任务和未来近地天体作为空间资源的利用。最后，IRTF的观测将通过麻省理工学院校园的远程观测进行，为大量无法前往望远镜的学生提供研究和教育的整合

AST 0506716BinzelWith this award, Dr. Richard Binzel and colleagues will achieve an increased understanding of the basic characteristics and the origins for the population of small bodies residing in orbits intersecting (or closely approaching) the orbit of the Earth. These near-Earth objects (NEOs) are important scientifically as they are the most immediate and representative source bodies for the delivery of meteorites to the Earth. Currently NEOs have mostly unknown origins from locations within the main asteroid belt and from extinct comets. A multi-year commitment of observing time (~2 nights per month over an initial period of two years) has been made by the NASA Infrared Telescope Facility (IRTF) at Mauna Kea, Hawaii for the purpose of enabling routine reconnaissance of newly discovered NEOs. NSF funding of this project will support the acquisition of these reconnaissance observations resulting in new spectral data for 80 to 100 NEOs per year, where all new data obtained will be reduced and publicly released in near-real time. In short order, this new reconnaissance program will eclipse the current number (~140) of NEOs having near-infrared spectral measurements. The specific science goals for these reconnaissance observations are: (1) To relate, as closely as possible, NEO spectral characteristics with major meteorite classes. (2) To quantitatively determine the relative consistency (or lack thereof) between the NEO population classes measured in space and the meteorite population classes determined by fall statistics on Earth. (3) To identify, as well as possible, specific main-belt source regions for specific classes of NEOs, and in turn, illuminate solar system origin links for specific meteorite types. (4) To characterize the properties of NEOs in comet-like orbits for the objective of illuminating asteroid-comet connections, thereby constraining the comet source fraction for NEOs. (5) To measure the spectral characteristics of NEOs residing in orbits reachable with propulsion requirements 7 km/sec, so that mission planning can be driven by scientific criteria (basic knowledge of the target properties) rather than by simple dynamical requirements. (6) Separately evaluate the compositional properties of the potentially hazardous asteroid (PHA) subgroup, to illuminate any difference in the relative hazard posed by these most closely approaching objects compared with the broader NEO population. Dr. Binzel and his team bring extensive spectroscopic experience to this project with more than 10 refereed publications and ~140 NEO observations obtained within the first two years of the prior three year funding period, and a substantially longer track record in asteroid research.The long-term interests of society dictate that we achieve an understanding of the NEO population for assessing their impact hazard and potential for natural resource utilization in space. Linking astronomical measurements of NEOs to laboratory measurements of meteorites provides a broad connection across different scientific disciplines. Identifying source regions for NEOs linked to meteorite classes anchors a wealth of laboratory meteorite data on solar system formation conditions to distinct locations as important boundary conditions for forming planets in our own solar system and beyond. The proximity of NEOs make them the most easily accessible destinations for spacecraft exploration, making their reconnaissance critical for both American and international space exploration planning, including possible future human missions and future utilization of NEOs as space resources. Finally, the IRTF observations are to be conducted by remote observing from the MIT campus, allowing the integration of research and education for a substantial number of students who could not otherwise travel to the telescope.***