| 近地小行星(10302) 1989 ML和(4660) Nereus的轨道特征及演化分析 |
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| 引用本文： | 陈媛媛,马月华.近地小行星(10302) 1989 ML和(4660) Nereus的轨道特征及演化分析[J].天文学报,2021,62(5):49. |
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| 作者姓名： | 陈媛媛 马月华 |
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| 作者单位： | 中国科学院紫金山天文台 南京 210023;中国科学院行星科学重点实验室 南京 210023 |
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| 基金项目： | 国家自然科学基金项目(11633009、11273067、11761131008), 中国科学院战略性先导科技专项(B类)(XDB41000000), 江苏省自然科学基金项目(BK20191512), 民用航天预研项目(D020304、D020302)和小行星基金会资助 |
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| 摘 要： | 近地小行星(10302) 1989 ML和(4660) Nereus作为下一代深空探测的候选目标一直备受关注. 在考虑太阳系主要天体的动力学背景下, 通过计算最大Lyapunov指数(MLE)及MEGNO (Mean Exponential Growth factor of Nearby Orbits)指数讨论它们的稳定性. 同时, 对每个小行星, 在其观测误差范围内按多元正态分布各选取1000个克隆粒子, 通过统计分析显示这两个小行星在10万年内可能的运动范围, 给出半长径-偏心率空间中的出现次数分布图, 并统计小行星与地球或其他大行星之间的密近交汇及碰撞的概率. 此外还对这两个小行星的标称轨道进行长期共振、Kozai共振及平运动共振的动力学分析. 综上得出结论, 1989 ML处在平运动共振主导的区域, 发生密近交汇的概率较小, 从而其轨道相对较稳定; 而Nereus处在地球的密近交汇区域, 轨道极不稳定.
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| 关 键 词： | 天体力学 行星和卫星: 动力学演化和稳定性 矮行星 小行星: 个别: (10302) 1989 ML (4660) Nereus |
| 收稿时间： | 2020/12/28 0:00:00 |
Analysis of Orbital Characteristics and Evolution of Near-Earth Asteroids (10302) 1989 ML and (4660) Nereus |
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| CHEN Yuan-yuan,MA Yue-hua.Analysis of Orbital Characteristics and Evolution of Near-Earth Asteroids (10302) 1989 ML and (4660) Nereus[J].Acta Astronomica Sinica,2021,62(5):49. |
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| Authors: | CHEN Yuan-yuan MA Yue-hua |
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| Institution: | Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210023;Key Laboratory of Planetary Sciences, Chinese Academy of Sciences, Nanjing 210023 |
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| Abstract: | Near-Earth Asteroids (10302) 1989 ML and (4660) Nereus have attracted much attention as candidates for deep space explorations of the next generation. In the study, the maximum Lyapunov exponent (MLE) and MEGNO index (Mean Exponential Growth factor of Nearby Orbits) are calculated after considering the effects of major objects of the Solar system and the stability of these two asteroids are discussed. For each asteroid, 1000 clonal particles are generated from a multivariate normal distribution within the observational uncertainties. The statistical results display probable motion regions of each asteroid within 0.1 million years, and provide distributions of occurrence times in the phase space of semi-major axis versus eccentricity, and count probability of close encounters and collisions between asteroid and Earth or other planets. Further, secular resonance, Kozai resonance and mean motion resonance are analyzed for nominal orbits of the two asteroids. By these analyses above, we concluded that 1989 ML is in the region dominated by mean motion resonances with terrestrial planets, and the probability of close encounters with them is relatively small. Therefore, its orbit is relatively stable. For Nereus, it is located in the close-encounter region of the Earth with an extremely unstable orbit. |
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| Keywords: | celestial mechanics planets and satellites: dynamical evolution and stability minor planets asteroids: individual: (10302) 1989 ML (4660) Nereus |
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