JpGU-AGU Joint Meeting 2017

講演情報

[JJ] ポスター発表

セッション記号 P (宇宙惑星科学) » P-PS 惑星科学

[P-PS07] [JJ] 惑星科学

2017年5月25日(木) 13:45 〜 15:15 ポスター会場 (国際展示場 7ホール)

コンビーナ:鎌田 俊一(北海道大学 創成研究機構)、岡本 尚也(千葉工業大学惑星探査研究センター)

[PPS07-P10] 楕円軌道惑星による小天体の一時捕獲

*樋口 有理可1井田 茂2 (1.東京工業大学、2.東京工業大学地球生命研究所)

キーワード:火星衛星、小惑星

We have investigated the probability of temporary capture of asteroids in eccentric orbits by a planet in a circular or an eccentric orbit by analytical and numerical calculations. We found that in the limit of the circular orbit, the capture probability is ~0.1% of encounters to the planet's Hill sphere, independent of planetary mass and semimajor axis. In general, the temporary capture becomes difficult, as the planet's eccentricity (ep) increases. We found that the capture probability is almost independent of ep until a critical value (epc) that is given by ~5 times of Hill radius scaled by the planet's semimajor axis. For ep> epc, the probability decreases approximately in proportional to ep-1. The current orbital eccentricity of Mars is several times larger than epc. However, since the range of secular change in Martian eccentricity overlaps ep, the capture of minor bodies by the past Mars is not ruled out.