Simultaneous Nadir Overpasses (SNOs) between GOES-15 and NPP
TLE Epoch: 2018 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)
 09/22/2018   22:40:34   (  -0.34,-135.52) (  -1.09,-138.91)  386.23                80
 09/23/2018   22:24:30   (  -0.34,-135.54) (  -0.09,-134.37)  132.23                80
 09/25/2018   10:46:19   (   0.33,-135.60) (   1.23,-139.65)  462.05                80
 09/26/2018   10:24:55   (   0.34,-135.61) (   0.24,-135.12)   55.48                80
 09/28/2018   22:28:08   (  -0.33,-135.59) (  -0.40,-135.90)   34.67                80
 09/29/2018   22:12:03   (  -0.33,-135.60) (   0.60,-131.36)  482.73                80
 10/01/2018   10:33:52   (   0.31,-135.65) (   0.54,-136.64)  113.14                80
 10/02/2018   10:12:28   (   0.32,-135.64) (  -0.46,-132.11)  403.07                80
 10/03/2018   22:34:25   (  -0.30,-135.59) (  -0.69,-137.42)  207.46                80
 10/04/2018   22:18:21   (  -0.31,-135.59) (   0.31,-132.88)  309.00                80