Far from random: dynamical groupings among the NEO population

C. de la Fuente Marcos, R. de la Fuente Marcos
(Submitted on 7 Dec 2015)

Among the near-Earth object (NEO) population there are comets and active asteroids which are sources of fragments that initially move together; in addition, some NEOs follow orbits temporarily trapped in a web of secular resonances. These facts contribute to increasing the risk of meteoroid strikes on Earth, making its proper quantification difficult. The identification and subsequent study of groups of small NEOs that appear to move in similar trajectories are necessary steps in improving our understanding of the impact risk associated with meteoroids. Here, we present results of a search for statistically significant dynamical groupings among the NEO population. Our Monte Carlo-based methodology recovers well-documented groupings like the Taurid Complex or the one resulting from the split comet 73P/Schwassmann-Wachmann 3, and new ones that may have been the source of past impacts. Among the most conspicuous are the Mjolnir and Ptah groups, perhaps the source of recent impact events like Almahata Sitta and Chelyabinsk, respectively. Meteoroid 2014 AA, that hit the Earth on 2014 January 2, could have its origin in a marginally significant grouping associated with Bennu. We find that most of the substructure present within the orbital domain of the NEOs is of resonant nature, probably induced by secular resonances and the Kozai mechanism that confine these objects into specific paths with well defined perihelia.

Comments: 11 pages, 15 figures. Accepted for publication in Monthly Notices of the Royal Astronomical Society
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
DOI: 10.1093/mnras/stv2885
Cite as: arXiv:1512.02139 [astro-ph.EP] (or arXiv:1512.02139v1 [astro-ph.EP] for this version)
Submission history
From: Ral de la Fuente Marcos
[v1] Mon, 7 Dec 2015 17:42:58 GMT (4469kb)
http://arxiv.org/abs/1512.02388