On the 3-Dimension dynamics in 99942 Apophis vicinity

The close approach of the Near-Earth Asteroid 99942 Apophis with Earth in 2029 will shed light on this irregularly shaped object. Since its discovery in 2004, studies, observations, and missions to this object have been performed or planned. Brozović et al. (2018) derived the most recent polyhedron shape model of Apophis. The shape provides an accurate model to study the dynamics around the asteroid. In this work, we aim to study the dynamics around 99942 Apophis. We use the shape model to build a MASCON(mass concentration) model(Geissler et al. 1996) and we use this model to compute the Poincaré Surface of Section(PSS) as proposed by Borderes-Motta & Winter (2017). With this approach, we can map the dynamics around an irregular body, identifying families of periodic and quasi-periodic orbits, and regions of chaos. The stable regions mapped by the PSS indicate where observation missions can seek for structures of meteoroids orbiting the asteroid. Our study can also provide valuable information for space missions to the asteroid, such as safe regions where a spacecraft can pass though to approach to the asteroid. In future works, we will also study the effect of the Earth's gravitational perturbation during the 2029 approach on the families of periodic orbits.

References:

Borderes-Motta, G. & Winter, O. C. 2017, Monthly Notices of the Royal Astronomical Society, 474, 2452 (https://doi.org/10.1093/mnras/stx2958)
Brozović, M., Benner, L. A., McMichael, J. G., et al. 2018, Icarus, 300, 115–128 (https://doi.org/10.1016/j.icarus.2017.08.032)
Geissler, P., Petit, J. M., Durda, D. D., et al. 1996, Icarus, 120, 140 (https://doi.org/10.1006/icar.1996.0042)