Near-Earth flux of small bodies of cometary origin

目的：周期彗星总数(PC)和与行星的撞击概率的准确估计在分析行星及其卫星上留下的陨石坑统计数据时非常重要。本研究的目的是通过对PC机轨道的长期数值积分，得到正确的撞击概率及其总数估计。方法：对228颗周期小于1000年、+/-3万年的PC机的轨道进行积分。主要结果是：(1)我们发现与木星相互作用的不可见PC的总数大约是可见PC的30倍。(2)发现用Opik-Wehorill模型估计的PC与内行星的传统碰撞概率被高估了10-40倍。

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.