Simultaneous Nadir Overpasses (SNOs) between GOES-17 and NPP
TLE Epoch: 2021 9 18.  Predictions up to the next  14.0 days:

     Date     Time(GOES-17)   GOES-17 Lat/Lon  NPP Lat/Lon    Distance(km)  Time Diff(sec)
 09/19/2021   22:47:20   (  -0.03,-137.19) (  -0.82,-140.72)  402.40                80
 09/20/2021   22:31:15   (  -0.03,-137.19) (   0.18,-136.19)  113.74                80
 09/22/2021   10:50:24   (   0.03,-137.19) (   0.99,-141.46)  486.56                80
 09/23/2021   10:34:19   (   0.03,-137.19) (  -0.02,-136.93)   29.33                80
 09/25/2021   22:34:52   (  -0.03,-137.16) (  -0.14,-137.70)   61.78                80
 09/26/2021   22:18:47   (  -0.03,-137.15) (   0.86,-133.17)  453.42                80
 09/28/2021   10:37:56   (   0.02,-137.13) (   0.31,-138.44)  148.59                80
 09/29/2021   10:21:51   (   0.02,-137.12) (  -0.69,-133.91)  366.04                80
 09/30/2021   22:41:09   (  -0.01,-137.08) (  -0.46,-139.22)  242.35                80
 10/01/2021   22:25:04   (  -0.01,-137.07) (   0.54,-134.68)  271.96                80