Impactor incident speed v_i as a function of the initial period T₀ for m_i = 1 m_⊕, obtained through angular momentum transfer for the most probable impact parameter b = 2/3 R_c. a) α = 0°, b) α = 29.58°, c) α = 60°, d α = 90°, e) α = 130°, and f) α = 170°. The upper constraint on v_i (v_iM) is depicted by dotted lines while the lower constraint on v_i (v_im) is shown by dashed lines. v_iM and v_im are obtained from simple dynamical constraints.