On the orbital evolution of meteoroid 2020 CD3, a temporarily-captured orbiter of the Earth-Moon system
C. de la Fuente Marcos, R. de la Fuente Marcos
(Submitted on 20 Mar 2020)
Any near-Earth object (NEO) following an Earth-like orbit may eventually be captured by Earth’s gravity during low-velocity encounters. This theoretical possibility was first attested during the fly-by of 1991 VG in 1991-1992 with the confirmation of a brief capture episode —for about a month in February 1992. Further evidence was obtained when 2006 RH120 was temporarily captured into a geocentric orbit from July 2006 to July 2007. Here, we perform a numerical assessment of the orbital evolution of 2020 CD3, a small NEO found recently that could be the third instance of a meteoroid temporarily captured by Earth’s gravity. We confirm that 2020 CD3 is currently following a geocentric trajectory although it will escape into a heliocentric path by early May 2020. Our calculations indicate that it was captured by the Earth in 2016 (median). This episode is longer than that of 2006 RH120. Prior to its capture as a minimoon, 2020 CD3 was probably a NEO of the Aten type, but an Apollo type cannot be excluded; in both cases, the orbit was very Earth-like, with low eccentricity and low inclination, typical of an Arjuna-type meteoroid. A few clone orbits remained geocentric for nearly a century, opening the door to the existence of yet-to-be-detected minimoons that are relatively stable for time-scales comparable to those of unbound quasi-satellites such as (469219) Kamo`oalewa. In addition, nearly 10 per cent of the experiments led to brief moonmoon episodes in which the value of the selenocentric energy of 2020 CD3 became negative.
Comments: 6 pages, 4 figures, 2 tables. Accepted for publication in Monthly Notices of the Royal Astronomical Society. Abstract abridged
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2003.09220 [astro-ph.EP] (or arXiv:2003.09220v1 [astro-ph.EP] for this version)
Submission history
From: Raúl de la Fuente Marcos
[v1] Fri, 20 Mar 2020 12:13:55 UTC (1,563 KB)
