one of many small solid celestial bodies thought to have existed at an early stage in the development of the solar system
双语例句
1. Thus, if the majority of the small amounts of water in a planetesimal reaches a planetary surface as its magma solidifies, this would be enough to form oceans that are similar to Earth's.
因此一个行星表面大部分的微量水元素到达岩浆的表面就凝固了，这将足够形成像地球上这样的海洋。
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2. 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.
3. 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.
