Astronomy8 papers
Binary asteroids
IŽ
Ivana Milić Žitnik
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AstronomyNiche
intermediate
Dancing with Venus in the shadow of the Earth: a pair of genetically related near-Earth asteroids trapped in a mean-motion resonance
C de la Fuente Marcos & R de la Fuente Marcos (2018)
- Published
- Nov 15, 2018
- Journal
- Monthly Notices of the Royal Astronomical Society: Letters · Vol. 483 · No. 1
- DOI
- 10.1093/mnrasl/sly214
At a Glance
Two near-Earth asteroids form a long-lived “faux-binary” because both are trapped in Venus’s 3:5 mean-motion resonance.
Summary
This paper reports an unusually tight, dynamically coherent near-Earth asteroid pair (2017 SN16 and 2018 RY7) whose proximity persists far longer than typical NEA orbit randomization would allow. Using N-body integrations with uncertainty sampling, the authors show both objects are concurrently trapped in the 3:5 mean-motion resonance with Venus, which locks their average angular speeds and prevents secular drift in their relative mean longitude, creating a quasi-satellite-like (but non-gravitationally bound) configuration. Statistical comparison against the debiased NEOPOP steady-state model finds a significant overabundance of similar orbits relative to expectations, supporting a recent in situ origin rather than standard delivery pathways from the main belt. The most plausible formation scenarios are YORP-driven rotational fission or binary dissociation occurring while resonantly confined, suggesting resonances can preserve genetic links among NEAs long enough to be observed and tested (e.g., via spectroscopy).
Method Snapshot
Direct N-body integrations with clone orbits from covariance matrices plus statistical comparison to the NEOPOP synthetic NEA population model.
Background
Basic celestial mechanics of near-Earth asteroid dynamics, including mean-motion resonances and Yarkovsky/YORP effects.