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Planetary Formation relevant to Titius-Bode's Law

与提丢斯-波德定律相关的行星形成

基本信息

批准号：
07454114
负责人：
NAKAZAWA Kiyoshi
金额：
$ 4.99万
依托单位：
TOKYO INSTITUTE OF TECHNOLOGY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1997
项目状态：
已结题

项目摘要

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

在过去的十年里，人们一直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。如木星和土星在原太阳星云，被认为是在很短的时间内消散，相当于约一千万年。另一个原因是我们无法解释目前行星之间的距离。到目前为止，人们已经接受了一个行星形成的顺序，即在太阳附近运行的类地行星比在远离太阳的轨道上运行的类木行星积累得更快。为了考虑这两个大问题，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，类木行星的强引力是再现目前类地行星排列的必要条件。 ...更多信息木星行星的形成过程。要产生一个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，并使其足够大，以吸引星云中的气体。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。在目前的木星区域，要在千万年内产生如此大的固体核心是非常困难的。研究了固体矿石的成藏过程和岩心对气体的捕获过程。总结结果，我们得出如下结论。(1)一千万年后，有可能产生一个固体核心，其质量与目前木星的轨道相当。(2)由于星子在其生长的最后阶段向实核聚集的速率下降，只有几倍地球质量的实核可以吸引原太阳星云中的气体，由此我们得出结论：类木行星可能是在现代类地行星形成之前聚集起来的。因此，研究类木行星强引力作用下地球板块晚期堆积的必要性增加。少