Temporary capture in the Sun–Earth system with dissipative effects

ABSTRACT Temporary capture of small particles by the Earth in the Sun–Earth system is studied by considering dissipative effects (the Poynting–Robertson effect, the solar wind, and the Yarkovsky effect) on particles with different sizes ranging from centimetres to kilometres. Our studies find a dependence of the long-term orbital element distribution on the particle size. This dependence causes the capture efficiency to also depend on the particle size. The computed capture efficiency increases when the particle size decreases. A critical size of approximately 1 m is proposed. When the particle size is larger than this, the dependence can be neglected. We also find that the particle’s steady-state orbital element distribution near the Earth’s orbit is dependent on its own spin state. For cm-sized particles, the capture efficiency for prograde-spin particles is approximately 1.7 times that in the pure gravity case, while for retrograde-spin particles, it is approximately 2.4 times. Moreover, our studies further find that dissipative effects not only extend the lifetime of captured objects, but also broaden the capture window near the Earth and tend to shift the capture direction towards the areas ahead of and behind the Earth.