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

该项目将为提议小组关于近地小行星表面特性建模的工作提供新的支持。这些提议者开发了复杂的计算方法，既可从雷达观测中确定近地小行星的形状，又可预测其阳光照射表面发出的热红外辐射。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结果进行比较，研究小组将能够限制观测到的近地小行星的大小和表面反射率，并测试和改进热模型。该小组计划在该项目的三年期内每年获得6至10个近地小行星的雷达观测数据，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“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。这些结果将对太阳系科学产生更广泛的影响，因为热模型通常用于推断小天体的物理性质。这项研究将有助于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的现有计划积极追求。

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.