Simultaneous Nadir Overpasses (SNOs) between GOES-15 and NPP
TLE Epoch: 2018 9 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)
 09/21/2018   10:18:37   (   0.35,-135.53) (  -0.07,-133.60)  219.36                80
 09/22/2018   22:40:34   (  -0.34,-135.52) (  -1.09,-138.91)  386.26                80
 09/23/2018   22:24:30   (  -0.34,-135.54) (  -0.10,-134.37)  132.20                80
 09/25/2018   10:46:19   (   0.33,-135.60) (   1.24,-139.65)  462.10                80
 09/26/2018   10:24:55   (   0.34,-135.61) (   0.24,-135.12)   55.45                80
 09/28/2018   22:28:07   (  -0.33,-135.59) (  -0.40,-135.89)   34.73                80
 09/29/2018   22:12:03   (  -0.33,-135.60) (   0.60,-131.36)  482.67                80
 10/01/2018   10:33:52   (   0.31,-135.65) (   0.54,-136.64)  113.21                80
 10/02/2018   10:12:28   (   0.32,-135.64) (  -0.46,-132.11)  402.99                80
 10/03/2018   22:34:25   (  -0.30,-135.59) (  -0.70,-137.42)  207.53                80