Near-Earth Object Reconnaissance and Source Region Analysis

有了这个奖项，Richard Binzel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(NEO)具有重要的科学意义，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未知，它们来自主要小行星带内的位置和已灭绝的彗星。位于夏威夷莫纳克亚的美国宇航局红外望远镜设施(IRTF)作出了一项多年的观测时间承诺(最初两年，每月约2个晚上)，以便能够对新发现的近地天体进行例行侦察。国家科学基金会对该项目的资助将支持获取这些侦察观测数据，从而每年产生80至100个近地天体的新光谱数据，所有获得的新数据都将被减少，并近乎实时地公开发布。在短时间内，这一新的侦察计划将使目前拥有近红外光谱测量的近地天体数量(约140个)黯然失色。这些侦察观测的具体科学目标是：(1)尽可能密切地将近地天体光谱特征与主要陨石类别联系起来。(2)定量确定在空间测量的近地天体种群类别与由地球上的陨石统计数据确定的陨石种群类别之间的相对一致性(或缺乏一致性)。(3)尽可能查明特定类别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联系。(4)描述类彗星轨道上的近地天体的特性，以便阐明小行星-彗星之间的联系，从而限制近地天体的彗星来源比例。(5)测量位于具有7公里/秒推进要求的轨道上的近地天体的光谱特性，以便能够根据科学标准(目标特性的基本知识)而不是简单的动力学要求来进行飞行任务规划。(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天体与更广泛的近地天体群体相比构成的相对危险有何不同。Binzel博士和他的团队为这个项目带来了广泛的光谱经验，在前三年资助期的前两年里，他们发表了10多篇参考出版物和大约140次近地天体观测，在小行星研究方面的记录要长得多。社会的长期利益要求我们了解近地天体人口，以评估他们在太空中的撞击危险和自然资源利用的潜力。将近地天体的天文测量与陨石的实验室测量联系起来，提供了跨越不同科学学科的广泛联系。查明与陨石类有关的近地天体的源区，可以将大量关于太阳系形成条件的实验室陨石数据固定到不同的位置，作为在我们自己的太阳系内外形成行星的重要边界条件。近地天体的接近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，包括未来可能的人类飞行任务和近地天体作为空间资源的未来利用。最后，IRTF的观测将通过从麻省理工学院校园进行远程观测进行，使大量无法前往望远镜的学生能够将研究和教育结合起来。*

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.***