Dependence of ejection velocities of individual fragments on cluster age (solid curves). The dashed blue curve corresponds to the mean ejection velocity. The vertical lines correspond to different ages: the age determined from the minimum of the initial kinetic energy of all fragments is ∼2.4 days (red line), while the minimum of the mean ejection velocity corresponds to an age of ∼2.0 days (blue line). The age corresponding to the formation at the distance of the semi-major axis of the Moon's orbit (∼9 hours) is shown in black.