P - T多益單字1000 - planetesimal 中文 - EN166

planetesimal n.,adj.【天文學】微星(的)。

planetesimal hypothesis
Models of the solar system ' s early history posit that the frequency of impacts should have tapered off between 4 . 5 billion and four billion years ago because most of the planetesimals ? the small rocky bodies that formed from the solar nebula ? were gradually cast out of the inner solar system or absorbed by the outer planets 描述太陽系早期歷史的模式假設，撞擊頻率應該在45 ~ 40億年前趨緩，因為大部份的微行星（由太陽星云形成的小型石質天體）逐漸被驅逐出內太陽系或被外行星吸收。
When the solar system was newly formed , the huge gravity of jupiter pulled planetesimals away from the sun , indirectly putting the earth under a collision barrage of objects of various sizes during the first hundred millions of years after the formation of the earth . hese violent impacts increase the amount of basic elements of life , water and organic compounds , on earth 在太陽系形成之初，木星巨大的重力把組成行星的物質牽引離開太陽，間接令地球在它形成后的最初數億年間，飽受不同大小的物體撞擊，這些猛烈的撞擊為地球增添了不少構成生命的重要元素水和其它有機化合物。
They may have been a source of part of the atmosphere of the terrestrial planets , and they are believed to have been the planetesimal - like building blocks for some of the outer planets and their satellites 他們本來可能是地球行星大氣層的來源之一，而目前的說法一直是他們是類星子堆積塊，由一些外部行星和他們的衛星所造成。
They may have been a source of part of the atmosphere of the terrestrial planets , and they are believed to have been the planetesimal - like building blocks for some of the outer planets and their satellites 它們可能是陸地行星大氣的部分來源，他們也被認為是一些外層行星及其衛星的像星子一樣的構成石塊。
During accretion , the kinetic energy of the colliding planetesimals was converted into thermal energy , so the earth grew extremely hot as it came together 在增生階段，小行星體的碰撞動能轉化成了熱能，因此當它聚集到一塊時地球變得非常熱。
Final accumulation of planetarysized objects is generally believed to come from the gravitational relaxation of the disk of planetesimals . 行星大小的天體的最終積累成功，一般認為歸因于星子圓盤的引力弛緩。