Simulation of a contact binary breakup. The spatial distribution of SPH particles is shown within a limited range of z ∈ (−1, 1) km and for t = 500 s. Colors correspond to the specific internal energy U in J kg⁻¹. The primary was dispersed after a collision with the impactor (not shown). The secondary (on the right) was squeezed by a low-speed collision with the primary. In the reaccumulation phase, the primary and the secondary eventually provide the first andsecond largest remnants in the synthetic family.