planetesimal

1. When the planetary migration occurs under the tidally interaction of a planet and a disk of gas or a planetesimal, the orbital parameters, especially, semi-major axis, of this planet will be altered.
   行星迁移发生在行星与气体或星子的星盘之间进行潮汐相互作用时，这造成行星轨道参数，特别是半主轴的变更。
2. The planetesimal accumulated formation style and the initial inhomogeneity of chemical compositions of the Earth had constrained strongly on the non homogeneity and non uniform evolution process of the Earth at late stages.
   地球的星子堆积形成方式和初始化学成分的不均一性制约着地球后期的非均一、非均变演化过程。
3. We investigate the effects of gas-disk gravity on the planetesimal dynamics in inclined binary systems.
   本文以大倾角双星系统中星子碰撞生长过程为背景，研究了气体盘的引力和阻力对Kozai效应的影响。

noun

1. one of many small solid celestial bodies thought to have existed at an early stage in the development of the solar system