APOPHIS – effects of the 2029 Earth’s encounter on the surface and nearby dynamics

Abstract

The 99942 Apophis close encounter with Earth in 2029 may provide information about asteroid’s physical characteristics and measurements of Earth’s effects on the asteroid surface. In this work, we analysed the surface and the nearby dynamics of Apophis. The possible effects of its 2029 encounter on the surface and environment vicinity are also analysed. We consider a 340 metres polyhedron with a uniform density (1.29 g·cm−3, 2.2 g·cm−3 and 3.5 g·cm−3). The slope angles are computed, as well their variation that arises during the close approach. Such variation reaches 4○ when low densities are used in our simulations and reaches 2○ when the density is high. The zero-velocity curves, the equilibrium points, and their topological classification are obtained. We found four external equilibrium points and two of them are linearly stable. We also perform numerical simulations of bodies orbiting the asteroid, taking into account the irregular gravitational field of Apophis and two extra scenarios of perturbations: the solar radiation pressure and the Earth’s perturbation during the close approach. The radiation pressure plays an important role in the vicinity of the asteroid, only cm-sized particles survived for the time of integration. For densities of 2.2 g·cm−3 and 3.5 g·cm−3, a region of 5 cm radius particles survived for 30 years of the simulation, and for 1.29 g·cm−3, only particles with 15 cm of radius survived. The ejections and collisions are about 30-50 times larger when the close encounter effect is added, but around 56-59% of particles still survive the encounter.

2001 SN263 – the contribution of their irregular shapes on the neighbourhood dynamics

“…Similarly to the section 3, we used the N-B M package to perform the simulations, but considering the solar radiation pressure (Valvano et al 2022). We considered the same initial conditions for the three regions.…”

Refinement of the convex shape model and tumbling spin state of (99942) Apophis using the 2020–2021 apparition data

“…Although Apophis's impact threat has disappeared, this asteroid remains an object of interest because of its close approach in 2029. The 2029 Earth encounter is expected to trigger varying degrees of alterations in the dynamics, spin states, and surface arrangements of Apophis due to the Earth's gravitational perturbation (Yu et al 2014;Souchay et al 2014Souchay et al , 2018DeMartini et al 2019;Hirabayashi et al 2021;Valvano et al 2022). Thus, the study of this asteroid will provide an excellent opportunity to examine the evolutionary process of its physical properties caused by planetary perturbation.…”

Refinement of the convex shape model and tumbling spin state of (99942) Apophis using the 2020-2021 apparition data

“…Although Apophis' impact threat has disappeared, this asteroid remains an object of interest because of its close approach in 2029. The Earth encounter of Apophis in 2029 is expected to trigger varying degrees of alterations in the dynamics, spinstates, and surface arrangements of Apophis due to the Earth's gravitational perturbation (Yu et al 2014;Souchay et al 2014Souchay et al , 2018DeMartini et al 2019;Hirabayashi et al 2021;Valvano et al 2022). Thus, the study of this asteroid will provide an excellent opportunity to examine the evolutionary process of its physical properties caused by planetary perturbation.…”