Planetary Formation relevant to Titius-Bode's Law

近十年来，人们致力于解决行星形成过程研究中的两大问题。一个问题是我们无法解释类木行星的形成。比如原太阳星云中的木星和土星，它被认为在很短的时间内消散，大约1000万年。另一个原因是我们无法解释目前行星之间的距离。迄今为止，围绕太阳运行的类地行星比远离太阳的类木行星积累得更快的行星形成顺序已被接受。考虑到这两个大问题，我们放弃了这种先入为主的观念，采用了一个新的工作假设，即类木行星是在类地行星积累之前形成的。我们认为，类木行星的强大引力对于再现类地行星目前的排列是必要的。首先，要采用可行的假设，就必须考虑类木行星的形成过程。要产生一颗含有大量氢气的类木行星，必须在原太阳星云中积累一个固体核心，并变得足够大，以通过其引力从星云中吸引气体。从太阳星云中吸引气体的固体核心的最小质量被认为是地球质量的10倍左右。在现在的木星区域，在1000万年的时间内很难产生如此大的固体内核。研究了某固体矿石的聚集过程和岩心捕集气体的过程。综上所述，我们得出如下结论。在1000万年的时间里，有可能产生一个质量相当于地球几倍的实心木星轨道。(2)由于星子在其成长的最后阶段对固体核心的积累速率下降，一个只有地球质量几倍的固体核心可以从原太阳星云中吸引气体。从这些结果我们得出结论，类木行星可能是在现在的类地行星形成之前积累起来的。因此，在类木行星的强引力作用下，研究类地板块后期积累的必要性增加了。少

In the last decade great efforts have been dedicated to solve two big problems in studies for planetary formation processes. One problem is that we could not explain the formation of Jovian planets. such as Jupiter and Saturn in the proto solar nebula which is considered to dissipate in a very little time as equal as about ten million years. And another is that we could not explain present distances between planets.Until now a sequence of the planetary formation that terrestrial planets orbiting near the Sun accumulated faster than the Jovian planets in the distant orbit from the Sun has been accepted. To consider the two big problems we abandoned this preconception and adopt a new working hypothesis that the Jovian planets are formed before the terrestrial planets are accumulated. We consider that strong gravity from the Jovian planets are necessary to reproduce present arrange of the terrestrial planets.At first, to adopt the working hypothesis it is necessary to consider the formati … More on process of the Jovian planets. To produce a Jovian planet which has great amount of hydrogen gas a solid core should accumulate in the proto solar nebula and become large enough to attract gas from nebula by it's gravity. The minimum mass of the solid core to attract gas from solar nebula was believed to be about 10 times earth's mass. It is very difficult to produce such large solid core in the present Jupiter region within ten million years. We studied the accumulation process of a solid ore and the gas capturing process by the core. Summarizing the result we conclude as follows.(1) It is possible to produce a solid core with few tines earth's mass at present Jupiter's orbit in ten million years.(2) Owing to the decline of the planetesimal accumulation rate to the solid core in the last stage of it's growth a solid core with only few times earth's mass can attract gas from the proto solar nebula.From thses results we conclude that jovian planets are possibily accumulated before present terrestrial planets are formed. So, the necessity to investigate the late stage accumulation of the terrestrial plates under the effect of strong gravity from the Jovian planets increases. Less