Simultaneous Nadir Overpasses (SNOs) between GOES-15 and NPP
TLE Epoch: 2017 12 23.  Predictions up to the next  14.0 days:

     Date     Time(GOES-15)   GOES-15 Lat/Lon  NPP Lat/Lon    Distance(km)  Time Diff(sec)
 12/24/2017   22:40:29   (   0.05,-135.28) (  -0.83,-139.08)  432.95                80
 12/25/2017   22:24:24   (   0.04,-135.27) (   0.22,-134.55)   82.02                80
 12/28/2017   10:27:26   (  -0.04,-135.29) (  -0.05,-135.29)    0.76                80
 12/30/2017   22:27:56   (   0.04,-135.16) (  -0.15,-136.05)  101.04                80
 12/31/2017   22:11:50   (   0.03,-135.13) (   0.85,-131.51)  412.71                80
 01/02/2018   10:30:58   (  -0.04,-135.16) (   0.32,-136.78)  185.20                80
 01/03/2018   10:14:52   (  -0.03,-135.13) (  -0.67,-132.25)  328.29                80
 01/04/2018   22:34:07   (   0.04,-135.01) (  -0.51,-137.55)  288.66                80
 01/05/2018   22:18:02   (   0.04,-134.98) (   0.49,-133.01)  224.47                80