Simultaneous Nadir Overpasses (SNOs) between GOES-15 and NPP
TLE Epoch: 2018 12 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)
 12/21/2018   10:12:01   (  -0.03,-128.67) (   0.68,-131.98)  376.04                80
 12/22/2018   09:55:55   (  -0.02,-128.66) (  -0.30,-127.44)  139.91                80
 12/23/2018   22:15:12   (   0.04,-128.54) (  -0.88,-132.74)  478.80                80
 12/24/2018   21:59:06   (   0.03,-128.53) (   0.09,-128.20)   36.96                80
 12/27/2018   09:59:29   (  -0.03,-128.62) (   0.06,-128.95)   37.75                80
 12/28/2018   09:43:25   (  -0.03,-128.61) (  -0.97,-124.42)  477.58                80
 12/29/2018   22:02:40   (   0.04,-128.47) (  -0.26,-129.71)  141.93                80
 12/30/2018   21:46:35   (   0.03,-128.46) (   0.78,-125.19)  373.50                80
 01/01/2019   10:05:44   (  -0.05,-128.56) (   0.35,-130.47)  216.72                80
 01/02/2019   09:49:38   (  -0.04,-128.55) (  -0.62,-125.93)  298.27                80