Simultaneous Nadir Overpasses (SNOs) between GOES-15 and NPP
TLE Epoch: 2017 9 21.  Predictions up to the next  14.0 days:

     Date     Time(GOES-15)   GOES-15 Lat/Lon  NPP Lat/Lon    Distance(km)  Time Diff(sec)
 09/22/2017   10:46:21   (   0.28,-135.40) (   1.25,-139.68)  488.94                80
 09/23/2017   10:24:56   (   0.29,-135.40) (   0.26,-135.15)   28.62                80
 09/25/2017   22:28:10   (  -0.28,-135.38) (  -0.39,-135.93)   62.64                80
 09/26/2017   22:12:06   (  -0.29,-135.39) (   0.60,-131.40)  454.88                80
 09/28/2017   10:33:55   (   0.27,-135.45) (   0.55,-136.68)  139.72                80
 09/29/2017   10:12:30   (   0.28,-135.45) (  -0.44,-132.14)  376.78                80
 09/30/2017   22:34:28   (  -0.26,-135.40) (  -0.73,-137.45)  234.05                80
 10/01/2017   22:18:24   (  -0.26,-135.40) (   0.32,-132.93)  282.74                80
 10/03/2017   10:40:14   (   0.24,-135.46) (   0.83,-138.21)  311.85                80
 10/04/2017   10:18:49   (   0.25,-135.46) (  -0.17,-133.67)  204.12                80