planetesimals and by gas accretion 4.The distances, spin periods and inclinations of the spin axes of the planets 5.The origin of asteroids, comets and planetary satellites 6.The initial temperature profile of the planets and 7.The blow-off of planetary protoatmospheres and of the protoplanetary...
TWO papers under the title "Gravitational Theory JL of Planetary Rotation", and "A New Theory of Planetary Formation", by J. Miller, have just appeared (J. Brit. Astro. Assoc., 52, 5 and 6, June and July 1942). Miller shows that a spherical body or a loose agglomeration of ...
A timetable for an evolutionary sequence of processes, which begins with the formation of the solar nebula being nearly in equilibrium and ends with formation of planets and satellites, is presented. Four main stages are discussed: (1) the collapse of a cloud and the formation of a gas disk...
explanation of the origin of the solar system according to which a rotating nebula cooled and contracted, flattening into a disk shape with a central bulge. The matter in the disk condensed into the planets, their moons, asteroids, and comets, while the great mass at the center became the ...
分析句子成分可 知,为了避免句子头重脚轻,it作形式主语,置于 句首。真正的主语为 that the formation of the sun, the planets, and other stars began with the condensation of an interstellar gas cloud It is believed that...为固定句型,意为“据说… … ,人们 认为 …” ...
I consider several problems of the evolution of the solar nebula, the precipitation of dust particles toward its central plane, and the possibility that a gravitational instability developed in the dust subdisk. A solution of the dispersion equation is given for the development of an instability in...
1.What is the main purpose of the lecture? A. To describe two new theories about the formation of rocky planets. B. To discuss competing theories about the formation of gas planets. C. To compare the composition of Jupiter, Saturn, Uranus, and Neptune. ...
Around the protostar, a large flat discof dust, rock, and ice, which would become the planets, moons, and asteroids in the solar system, collected.This initial stage in the formation of the solar system lasted approximately 100,000 years. Next,the planets formed through the process known as...
【解析】题干问的是：根据第 2 段，下列关于十八世纪太阳系起源理论的说法，哪一个是正确的？根据题干the origin of the solar system定位到段首句：关于太阳系起源的一个关键证据是，所有的行星都在同一个方向和几乎同一个平面上绕太阳公转，对应A选项。
Planets can arise during the formation of a star mainly due to excess angular momentum leading to the formation of an accretion-decretion disk of gas and dust around a single star or the components of a binary. It is the evolution of such disks that gives rise to planetary systems. A ...