Simultaneous Nadir Overpasses (SNOs) between GOES-15 and NPP
TLE Epoch: 2018 4 20.  Predictions up to the next  14.0 days:

     Date     Time(GOES-15)   GOES-15 Lat/Lon  NPP Lat/Lon    Distance(km)  Time Diff(sec)
 04/21/2018   22:27:31   (  -0.09,-135.40) (  -0.21,-135.95)   62.43                80
 04/22/2018   22:11:27   (  -0.10,-135.42) (   0.80,-131.42)  455.57                80
 04/24/2018   10:30:35   (   0.10,-135.43) (   0.36,-136.69)  143.58                80
 04/25/2018   10:14:31   (   0.10,-135.44) (  -0.65,-132.16)  374.33                80
 04/26/2018   22:33:47   (  -0.10,-135.47) (  -0.55,-137.46)  227.49                80
 04/27/2018   22:17:43   (  -0.10,-135.48) (   0.46,-132.93)  290.19                80
 04/29/2018   10:36:51   (   0.09,-135.49) (   0.71,-138.20)  309.76                80
 04/30/2018   10:20:46   (   0.10,-135.50) (  -0.31,-133.67)  207.67                80
 05/01/2018   22:40:03   (  -0.09,-135.51) (  -0.88,-138.97)  394.91                80
 05/02/2018   22:23:58   (  -0.09,-135.52) (   0.13,-134.44)  122.13                80
 05/04/2018   10:43:06   (   0.08,-135.52) (   1.04,-139.72)  479.14                80