2014 QS487 and (48514) 1993 FN22

Based on nominal orbital parameters, this is the result of a backward integration performed with Mercury6 (*) Bulirsch–Stoer run with a 0.05-day step, 1e-12 accuracy, and outputs every 100 days, integrating from JD 2461000.5 backward for 100 M days (~0.27 Myr)

(*) Chambers, J.E. 1999, “A Hybrid Symplectic Integrator that Permits Close Encounters between Massive Bodies,”

The following plot shows the relative velocity and distance following the time when the relative velocity was minimum:

Best wishes,

Alessandro Odasso