Investigation of near-Earth asteroid properties through a combination of infrared and radar observations

该项目将为提议小组在近地小行星表面属性建模方面的工作提供新的支持。提出者开发了复杂的计算方法，既可以从雷达观测中限制近地天体的形状，也可以预测从其阳光照射的表面发射的热红外辐射。通过将模型预测与使用空间和地面红外望远镜获得的观测进行比较，该小组将能够限制观测到的近地天体的大小和表面反射率(反照率)，以及测试和改进热模型。该小组计划在项目的三年期间每年获得6至10个近地天体的雷达观测数据，并获得这些物体和已有雷达数据的物体的红外光谱数据。他们将使用一个“热物理”代码对光谱进行建模，该代码考虑了多种重要的物理效应，包括热传导、阴影、表面的自辐射和表面的多次散射。这一结果将对太阳系科学产生更广泛的影响，因为热模型通常被用来推断小型天体的物理性质。这项研究将能够更好地量化近地小行星大小的不确定性，从而更好地评估小行星撞击地球造成的危害。学生(K-12、本科生和研究生)和教师的教育机会将通过参与机构现有的课程积极寻求。

This project will provide renewed support for the proposing team's work on the modeling of the surface properties of near-Earth asteroids (NEAs). The proposers have developed sophisticated computational methods for both constraining the shapes of NEAs from radar observations and for predicting the thermal infrared radiation emitted from their sunlit surfaces. By comparing the model predictions to observations obtained using space- and ground-based infrared telescopes, the team will be able to constrain the sizes and surface reflectivities (albedos) of the observed NEAs, as well as to test and refine the thermal models. The team plans to obtain radar observations of 6 to 10 NEAs per year in the 3-year term of the project, and to obtain infrared spectroscopic data for these objects and for objects with already-existing radar data. They will model the spectra using a "thermophysical" code that takes into account multiple important physical effects including heat conduction, shadowing, self-irradiation of the surface, and multiple scattering in the surface. The results will have wider implications for Solar System science, as thermal models are routinely used to infer the physical properties of small bodies. This study will enable a better quantification of the uncertainties in the sizes of NEAs and, therefore, a better assessment of the hazards from asteroid impacts on Earth. Educational opportunities for both students (K-12, undergraduate, and graduate) and teachers will be actively pursued through existing programs in place at the participating institutions.