Perihelion advance and Yarkovsky drift of near-Earth asteroids: asteroid physical properties, solar oblateness, and general relativity.

Jean-Luc Margot和Jon Giorgini博士将获得并解释12颗近地小行星（NEAs）的高精度雷达距离测量结果，这些小行星的轨迹受到太阳光，太阳形状和广义相对论效应的强烈影响。小行星的轨道受到太阳能的吸收和再发射的影响，即所谓的雅科夫斯基效应。这些运动变化将通过雷达测量加以量化，以便限制近地小行星的密度、组成和热特性。近地天体轨道的其他摄动是扁圆太阳引力场不均匀的结果。12个近地小行星的测距数据将通过测量小行星轨道的变化直接探测太阳内部的质量分布。还将通过量化深入太阳引力阱内部的近地小行星近日点推进量，改进广义相对论的雷达检验。GR效应可以从扁率效应中分离出来，因为它们对近地天体轨道的大小、偏心率和倾角有不同的依赖性。GR和扁率效应都可以从Yarkovsky漂移的独特特征中分离出来。大多数测量将使用阿雷西博望远镜上的行星雷达进行。对结果的分析将利用喷气推进实验室的轨道确定软件。在这一极端动态范围内的高精度测量将提供独特的观测限制，并将测试目前的小行星物理学、太阳物理学和基础物理学模型。

Drs. Jean-Luc Margot and Jon Giorgini will obtain and interpret high-precision radar range measurements on twelve near-Earth asteroids (NEAs) that have trajectories strongly affected by the light of the Sun, the shape of the Sun, and general relativistic effects. Asteroid orbits are influenced by the absorption and reemission of solar energy, the so-called Yarkovsky effect. These changes to the motion will be quantified with the radar measurements in order to constrain the densities, compositions, and thermal properties of NEAs. Other perturbations to NEA orbits arise as a result of the non-uniformity of the gravitational field of the oblate Sun. The ranging data to the twelve NEAs will provide a direct probe of the mass distribution in the Suns interior by measuring changes to the asteroid trajectories. Radar tests of general relativity (GR) will also be improved by quantifying the perihelion advance of NEAs that reach deep inside the gravitational well of the Sun. The GR effects can be separated from the effects of oblateness as they have a different dependence on the size, eccentricity, and inclination of the NEA orbits. Both GR and oblateness effects can be separated from the distinct signature of the Yarkovsky drift. Most of the measurements will be performed with the planetary radar on the Arecibo telescope. Analysis of the results will make use of orbital determination software at JPL. High precision measurements in this extreme dynamical regime will provide unique observational constraints and will test current models of asteroid physics, solar physics, and fundamental physics.