Evolution of a particle with U_∞ = 1.0 (﹩{{ \mathcal A }}_{0}﹩=1.2, e₀=0.61, i₀=47﹩\mathop{.}\limits^{\unicode{x000b0}}﹩8, closely coupled case) in orbital elements (﹩{ \mathcal A }﹩, e, i, left panels) and relative-velocity vectors (θ, ϕ, U_∞, right panels) scattered by a m_p = 1 × 10⁻⁴m_⊙ planet on a a_p = 1 au circular orbit. The gray regions mark ﹩{\unicode{120006}}﹩ > 1 (red curves), corresponding to where the Öpik framework fails. The blue region in the top-right panel represents the loss cone θ_loss (Equation (13)).