Simultaneous Nadir Overpasses (SNOs) between GOES-15 and NPP
TLE Epoch: 2018 9 11.  Predictions up to the next  14.0 days:

     Date     Time(GOES-15)   GOES-15 Lat/Lon  NPP Lat/Lon    Distance(km)  Time Diff(sec)
 09/12/2018   22:27:58   (  -0.38,-135.30) (  -0.52,-135.86)   64.19                80
 09/13/2018   22:11:55   (  -0.38,-135.34) (   0.53,-131.34)  455.89                80
 09/15/2018   10:33:44   (   0.37,-135.40) (   0.61,-136.62)  138.20                80
 09/16/2018   10:12:19   (   0.37,-135.42) (  -0.38,-132.08)  380.82                80
 09/17/2018   22:34:17   (  -0.36,-135.44) (  -0.78,-137.39)  222.01                80
 09/18/2018   22:18:12   (  -0.36,-135.47) (   0.21,-132.86)  297.29                80
 09/20/2018   10:40:02   (   0.35,-135.53) (   0.93,-138.14)  296.86                80
 09/21/2018   10:18:37   (   0.35,-135.55) (  -0.06,-133.60)  221.56                80
 09/22/2018   22:40:34   (  -0.33,-135.55) (  -1.09,-138.91)  383.32                80
 09/23/2018   22:24:30   (  -0.34,-135.57) (  -0.10,-134.38)  135.51                80