Spin state evolution of (99942) Apophis during its 2029 Earth encounter

We explore the effects of 2029 Earth encounter on asteroid (99942) Apophis' non-principal axis spin state, leveraging refined orbit, and inertia information provided by more recent optical radar observations. Propagating asteroids' coupled orbit rigid body attitude dynamics through flyby, we present range possible post-flyby states. These state distributions will be valuable for planning Apophis observation campaigns spacecraft missions, most notably OSIRIS-APEX. The simulations indicate that gravitationally induced changes to asteroid's tumbling periods rotational angular momentum direction (pole) likely significant measurable. For current estimates their uncertainties, is remain in a short mode (SAM) but its effective rate could halve or double. Its pole shift 10 degrees increase longitude while moving closer ecliptic plane. are very sensitive close approach mass distribution. With ground-based tracking encounter, this sensitivity help refine distribution knowledge. also discuss implications abrupt alteration Yarkovsky acceleration geophysical properties, identifying pathways surface internal changes, if contact binary. Comparison pre obtained from observations assess extent changes.