Orbital convergence of secular angles for the nominal orbits of (475 474) 2006 SZ152 and (525) Adelaide: (i) difference in longitude of node δΩ = Ω_{475 474} − Ω₅₂₅ (red line), (ii) difference in longitude of perihelion δϖ = ϖ_{475 474} − ϖ₅₂₅ (blue line) (osculating values in both cases). The abscissa is time to the past (in kyr). The secular angle differences stay very small for the past ≃ 600 kyr (within about one degree), but the precise nature of the convergence is not as good as in the previous two figures because of the likely contribution of the Yarkovsky acceleration in the orbital evolution of the smaller asteroid (475 474) 2006 SZ152 (see text).