双卫一
外观
![]() 摄于2022年9月 | |
发现[1] | |
---|---|
发现者 | Petr Pravec et al.[a] |
发现日期 | 2003年11月20日 |
编号 | |
其它名称 | S/2003 (65803) 1 |
轨道参数[2] | |
历元 7.5 2011年1月 (儒略日 2455873.0) | |
半长轴 | ±0.03 km (撞击前) 1.19 |
离心率 | ≤ 0.03 |
轨道周期 | 6262±0.0000027 hr ( 11.92111h 55m 18s; 撞击前)[2] 11h 23m ± 2m (撞击后)[3][b] |
平均轨道速度 | (撞击前) 0.174 m/s |
平近点角 | °±1.8° 89.2 |
轨道倾角 | ±1.8° 相对于 168.6°黄道[c] |
隶属天体 | 双生星 |
物理特征 | |
大小 | 208 米 × 160 米 × 133 米[6] |
质量 | ×109 kg (推测) ~5[6] |
自转周期 | 潮汐锁定? |
反照率 | ±0.04 0.15 |
光谱类型 | S-型小行星 |
绝对星等(H) | ±0.2 21.3[1] |
双卫一是近地天体双生星的一颗小行星卫星。它的直径为170米(560英尺),与罗马斗兽场相当,重约480万吨。它与双生星中心相距约1190米[7]。2003年,有人在翁德热约夫天文台发现了双卫一。2020年6月,国际天文联会将这颗小行星卫星命名为双卫一[8]。2022年9月,美国太空总署在开展双小行星改道测试时将双卫一列为撞击目标,并故意让一个航天器撞向双卫一,目的是改变双卫一的轨迹[9]。
备注
[编辑]- ^ Astronomers involved in the discovery of Dimorphos include Petr Pravec, L.A.M. Benner, M.C. Nolan, P. Kusnirak, D. Pray, J.D. Giorgini, R.F. Jurgens, 史蒂文·J·奥斯特罗, J.-L. Margot, C. Magri, A. Grauer, and S. Larson. The discovery used lightcurve and radar observations from the 喷气推进实验室, Pasadena, 加利福尼亚州; 阿雷西博天文台, Arecibo, 波多黎各; and 翁德热约夫天文台, Ondřejov, 捷克. [1]
- ^ Orbital parameters are those after the impact of DART, which changed the 轨道周期 by 32 minutes. Other possibly changed parameters remain to be reevaluated.[3]
- ^ Scheirich and Pravec (2022) give the Dimorphos's orbit pole orientation in terms of 黄道坐标系, where λ is 黄道坐标系 and β is 黄道坐标系.[4](p. 4) β is the angular offset from the 黄道, whereas 轨道倾角 i with respect to the ecliptic is the angular offset of the 黄极 from the 黄极, at β = +90° ; i with respect to the ecliptic would be the 角 of β.[5] Therefore, given β = –78.6° , i = 90° – (–78.6°) = 168.6° from the ecliptic.
参考文献
[编辑]- ^ 1.0 1.1 1.2 (65803) Didymos. www.johnstonsarchive.net. [2021-11-11]. (原始内容存档于2020-10-23).
- ^ 2.0 2.1 Naidu, Shantanu P.; Chesley, Steven R.; Farnocchia, Davide; Moskovitz, Nick; Pravec, Petr; Scheirich, Petr; Thomas, Cristina; Rivkin, Andrew S. Anticipating the DART impact: Orbit estimation of Dimorphos using a simplified model. The Planetary Science Journal. October 2022, 3 (10): 234. Bibcode:2022PSJ.....3..234N. S2CID 252815897. arXiv:2210.05101
. doi:10.3847/PSJ/ac91c0.
- ^ 3.0 3.1 Dunbar, Brian. NASA Confirms DART Mission Impact Changed Asteroid's Motion in Space. NASA. 11 October 2022 [2022-10-11]. (原始内容存档于2023-03-07) (英语).
- ^ Scheirich, P.; Pravec, P. Preimpact Mutual Orbit of the DART Target Binary Asteroid (65803) Didymos Derived from Observations of Mutual Events in 2003–2021. The Planetary Science Journal. July 2022, 3 (7): 12 [2023-01-21]. Bibcode:2022PSJ.....3..163S. S2CID 250650906. doi:10.3847/PSJ/ac7233. 163. (原始内容存档于2022-07-19).
- ^ Coordinate transformations. Astronomy and Astrophysics. European Southern Observatory. January 1998 [17 June 2022]. (原始内容存档于17 June 2021).
- ^ 6.0 6.1 Nakano, Ryota; Hirabayashi, Masatoshi; Brozovic, M.; Nolan, M. C.; Ostro, S. J.; Margot, J. L.; et al. NASA's Double Asteroid Redirection Test (DART): Mutual Orbital Period Change Due to Reshaping in the Near-Earth Binary Asteroid System (65803) Didymos. The Planetary Science Journal. July 2022, 3 (7): 16 [2023-01-21]. Bibcode:2022PSJ.....3..148N. S2CID 250327233. doi:10.3847/PSJ/ac7566. 148. (原始内容存档于2022-09-27).
- ^ 观网财经. 人类首次行星防御演习,成功了. [2023-01-21]. (原始内容存档于2023-03-08).
- ^ Temming, Maria. An asteroid's moon got a name so NASA can bump it off its course. Science News. 29 June 2020 [1 July 2020]. (原始内容存档于2021-09-12).
- ^ Rincon, Paul. NASA DART asteroid spacecraft: Mission to smash into Dimorphos space rock launches. BBC News. 2021-11-24 [2021-11-25]. (原始内容存档于2022-01-01) (英国英语).