2023 SP50 and 152737 (1998 WF28)

 Backward simulation

Mercury6 package by J.E.Chambers (1999) ``A Hybrid Symplectic Integrator that Permits Close Encounters between Massive Bodies''. Monthly Notices of the Royal Astronomical Society, vol 304, pp793-799. 

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) Important integration parameters:

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 algorithm (MVS, BS, BS2, RADAU, HYBRID etc) = BS

 start time (days)=  2460106.5

) stop time (days) = 102458000.5

 stop time (days) = -1e8

 output interval (days) = 100

 timestep (days) = 0.05

 accuracy parameter=1.d-12

Result