No abstract

The asteroid Apophis is one of the most hazardous near Earth asteroids. As a result of the scatter ing of Apophis' potential trajectories after its close approach in 2029, and its possible approach in 2036, there are many dangerous trajectories including impact trajectories after 2036. The purpose of this study is to iden tify and investigate these trajectories. We use the Everhart integrator; the DE405, DE423, and EPM2008 eph emerides; and two sets of initial data for Apophis (those collected by NASA in 2006 and by the IAA in 2010). More than 50 possible encounters in this century are presented, including 13 encounters between 2036 and 2050. The minimum geocentric distances obtained using a different ephemeris and initial conditions differ little between themselves. Analogous results in (Yeomans et al., 2009) are consistent with our results.

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A code for constructing self-gravitating galactic models in a given potential by Schwarszchild's method was developed. As an example a distribution function for a two-component model of the Galactic potential by Kutuzov and Ossipkov was found.