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

Jean-Luc Marget博士和Jon Giorgii博士将获得并解释12颗近地小行星(NEA)的高精度雷达距离测量，这些小行星的轨迹受到太阳光、太阳形状和一般相对论效应的强烈影响。小行星轨道受到太阳能吸收和再发射的影响，即所谓的雅可夫斯基效应。运动的这些变化将通过雷达测量来量化，以限制近地天体的密度、组成和热性质。对NEA轨道的其他扰动是由于扁平太阳引力场的不均匀造成的。十二个近地天体的测距数据将通过测量小行星轨迹的变化来直接探测太阳内部的质量分布。广义相对论(GR)的雷达测试也将通过量化到达太阳引力井深处的近地天体的近日点推进来改进。GR效应可以与扁率效应分开，因为它们对NEA轨道的大小、偏心率和倾角有不同的依赖关系。GR效应和扁率效应都可以从Yarkovsky漂移的明显特征中分离出来。大部分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。在这种极端动力状态下的高精度测量将提供独特的观测约束，并将测试当前的小行星物理、太阳物理和基础物理模型。

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.