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)  455.53                80
 04/24/2018   10:30:35   (   0.10,-135.43) (   0.37,-136.69)  143.68                80
 04/25/2018   10:14:31   (   0.10,-135.44) (  -0.64,-132.16)  374.20                80
 04/26/2018   22:33:47   (  -0.10,-135.47) (  -0.56,-137.46)  227.62                80
 04/27/2018   22:17:42   (  -0.10,-135.48) (   0.46,-132.93)  290.02                80
 04/29/2018   10:36:51   (   0.09,-135.48) (   0.71,-138.20)  310.00                80
 04/30/2018   10:20:46   (   0.10,-135.49) (  -0.30,-133.67)  207.40                80
 05/01/2018   22:40:03   (  -0.09,-135.51) (  -0.89,-138.97)  395.17                80
 05/02/2018   22:23:58   (  -0.09,-135.52) (   0.13,-134.44)  121.85                80