Topology of the outer evection resonance for m₂ ≪ m₁. Panels a andb: behavior of m₁ at two different distances from the planet (in all cases a₁ = a₂). In panel a, two libration islands at ψ₁ = 0° and 180° are connected by an unstable point that is shifted to positive values of e₁ cos ψ ₁. In panel b only a kinematic libration around ψ₁ = 180° is observed. Panel c: behavior of m₂ at the same distance from the planet as in panel a. In this case, the topology is the same, but the libration islands are rotated by −Δϖ. In all cases, Δϖ = 60°.