Simultaneous Nadir Overpasses (SNOs) between GOES-15 and NPP
TLE Epoch: 2017 9 10.  Predictions up to the next  14.0 days:

     Date     Time(GOES-15)   GOES-15 Lat/Lon  NPP Lat/Lon    Distance(km)  Time Diff(sec)
 09/12/2017   10:33:43   (   0.32,-135.20) (   0.65,-136.64)  163.83                80
 09/13/2017   10:12:20   (   0.33,-135.22) (  -0.39,-132.11)  354.56                80
 09/14/2017   22:34:17   (  -0.31,-135.22) (  -0.78,-137.42)  250.55                80
 09/15/2017   22:18:13   (  -0.32,-135.24) (   0.20,-132.88)  268.27                80
 09/17/2017   10:40:02   (   0.30,-135.31) (   0.95,-138.16)  325.02                80
 09/18/2017   10:18:39   (   0.31,-135.33) (  -0.09,-133.64)  193.00                80
 09/19/2017   22:40:36   (  -0.29,-135.31) (  -1.08,-138.95)  413.90                80
 09/20/2017   22:24:31   (  -0.30,-135.33) (  -0.09,-134.41)  104.76                80
 09/22/2017   10:46:21   (   0.28,-135.41) (   1.24,-139.69)  487.71                80
 09/23/2017   10:24:56   (   0.29,-135.42) (   0.25,-135.16)   30.06                80