Binary Asteroid Encounters with Terrestrial Planets: Timescales and Effects

Abstract

Many asteroids that make close encounters with terrestrial planets are in a binary configuration. Here we calculate the relevant encounter timescales and investigate the effects of encounters on a binary's mutual orbit. We use a combination of analytical and numerical approaches with a wide range of initial conditions. Our test cases include generic binaries with close, moderate, and wide separations, as well as seven well-characterized near-Earth binaries. We find that close approaches (<10 Earth radii) occur for almost all binaries on 1-10 million year timescales. At such distances, our results suggest substantial modifications to a binary's semi-major axis, eccentricity, and inclination, which we quantify. Encounters within 30 Earth radii typically occur on sub-million year timescales and significantly affect the wider binaries. Important processes in the lives of near-Earth binaries, such as tidal and radiative evolution, can be altered or stopped by planetary encounters.

8 pages, accepted to AJ

References in corpus (4)

• Do Planetary Encounters Reset Surfaces of Near Earth Asteroids?
• Orbits of Near-Earth Asteroid Triples 2001 SN263 and 1994 CC: Properties, Origin, and Evolution
• Near-Earth Binaries and Triples: Origin and Evolution of Spin-Orbital Properties
• Levy Flights of Binary Orbits due to Impulsive Encounters

Cited by in corpus (15)

• Asteroid Systems: Binaries, Triples, and Pairs
• Near-Earth Binaries and Triples: Origin and Evolution of Spin-Orbital Properties
• Near-Earth Asteroid Satellite Spins Under Spin-Orbit Coupling
• The Formation of the Wide Asynchronous Binary Asteroid Population
• Stability Regions Around the Components of the Triple System 2001 SN263
• Matching asteroid population characteristics with a model constructed from the YORP-induced rotational fission hypothesis
• The Role of Kozai Cycles in Near-Earth Binary Asteroids
• The formation mechanism of 4179 Toutatis' elongated bi-lobed structure in a close Earth encounter scenario
• Breakup of the Synchronous State of Binary Asteroid Systems
• Binary asteroid scattering around white dwarfs
• Small asteroid system evolution
• Gravitational disturbance on asteroidal ring systems by close encounter with a small object
• Multiple origins of asteroid pairs
• Semi-analytical near-Earth objects propagation: the orbit history of (35107) 1991 VH and (175706) 1996 FG3
• Orbits of very distant asteroid satellites