| Project/Area Number |
06640361
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Astronomy
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| Research Institution | National Astronomical Observatory |
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Principal Investigator |
NAKAMURA Tsuko National Astronomical Obs., Opt.& IR division, Associate Prof., 光学赤外線天文学研究系, 助教授 (80107474)
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| Co-Investigator(Kenkyū-buntansha) |
YOSHIKAWA Makoto Communications Research Laboratory, Head Researcher, 通信総合研究所, 主任研究員
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1995: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1994: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | Comets / Asteroids / Impact probability / 軌道進化 |
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| Research Abstract |
Purposes :
Exact estimates of total population of periodic comets (PC) and impact probabilities with planets are very important in analysis of cratering statistics imprinted on planets and their satellites. The purposes of this research are to obtain correct impact probabilities of PCs and their total number estimate through long-term numerical integration of their orbits.
Method :
We integrated the orbits of 228 PCs with period less than 1000 years, for +/- 30,000 years. The results of those orbital evolution and close encounters with planets are statistically analyzed.
Main results :
(1) We found that the total number of invisible PCs which interact with Jupiter is sbout 30 times as many as the number of observable PCs.
(2) It is found that the conventional impact probabilities of PCs with the inner Planets estimated by Opik-Wethrill model are 10-40 times overestimated.
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