Simultaneous Nadir Overpasses (SNOs) between GOES-15 and NPP
TLE Epoch: 2017 12 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)
 12/22/2017   10:37:19   (  -0.04,-135.39) (   0.61,-138.32)  333.54                80
 12/23/2017   10:21:13   (  -0.03,-135.38) (  -0.38,-133.78)  181.78                80
 12/24/2017   22:40:29   (   0.05,-135.28) (  -0.82,-139.08)  433.06                80
 12/25/2017   22:24:23   (   0.04,-135.27) (   0.17,-134.54)   81.86                80
 12/28/2017   10:27:26   (  -0.04,-135.29) (  -0.05,-135.29)    1.30                80
 12/30/2017   22:27:56   (   0.04,-135.16) (  -0.14,-136.05)  101.53                80
 12/31/2017   22:11:50   (   0.03,-135.13) (   0.85,-131.52)  412.17                80
 01/02/2018   10:30:58   (  -0.04,-135.15) (   0.32,-136.79)  185.90                80
 01/03/2018   10:14:52   (  -0.03,-135.12) (  -0.68,-132.25)  327.53                80