Simultaneous Nadir Overpasses (SNOs) between GOES-15 and NPP
TLE Epoch: 2018 6 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)
 06/22/2018   10:24:21   (  -0.05,-134.89) (  -0.01,-135.14)   28.09                80
 06/23/2018   10:08:17   (  -0.04,-134.93) (  -1.04,-130.61)  493.15                80
 06/24/2018   22:27:33   (   0.07,-135.00) (  -0.14,-135.91)  104.19                80
 06/25/2018   22:11:28   (   0.06,-135.04) (   0.89,-131.39)  416.67                80
 06/27/2018   10:30:36   (  -0.09,-135.08) (   0.29,-136.65)  179.48                80
 06/28/2018   10:14:31   (  -0.08,-135.12) (  -0.74,-132.12)  341.06                80
 06/29/2018   22:33:49   (   0.11,-135.18) (  -0.38,-137.44)  257.38                80
 06/30/2018   22:17:43   (   0.09,-135.21) (   0.60,-132.90)  262.90                80
 07/02/2018   10:36:51   (  -0.12,-135.24) (   0.53,-138.18)  334.10                80
 07/03/2018   10:20:46   (  -0.11,-135.27) (  -0.45,-133.63)  185.90                80
 07/04/2018   22:40:03   (   0.13,-135.32) (  -0.67,-138.95)  413.44                80