Simultaneous Nadir Overpasses (SNOs) between GOES-15 and NPP
TLE Epoch: 2017 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)
 09/20/2017   22:24:31   (  -0.30,-135.33) (  -0.11,-134.40)  104.65                80
 09/22/2017   10:46:20   (   0.28,-135.40) (   1.26,-139.68)  488.95                80
 09/23/2017   10:24:57   (   0.29,-135.41) (   0.22,-135.16)   28.62                80
 09/25/2017   22:28:10   (  -0.28,-135.38) (  -0.40,-135.93)   62.35                80
 09/26/2017   22:12:05   (  -0.29,-135.39) (   0.59,-131.40)  455.19                80
 09/28/2017   10:33:55   (   0.27,-135.46) (   0.56,-136.68)  139.45                80
 09/29/2017   10:12:31   (   0.28,-135.46) (  -0.49,-132.15)  377.12                80
 09/30/2017   22:34:27   (  -0.26,-135.40) (  -0.74,-137.45)  233.56                80
 10/01/2017   22:18:24   (  -0.26,-135.41) (   0.31,-132.93)  283.28                80
 10/03/2017   10:40:13   (   0.24,-135.47) (   0.84,-138.21)  311.32                80
 10/04/2017   10:18:49   (   0.25,-135.46) (  -0.16,-133.67)  204.69                80