Simultaneous Nadir Overpasses (SNOs) between GOES-18 and NOAA-21
TLE Epoch: 2023 6 20.  Predictions up to the next  14.0 days:

     Date     Time(GOES-18)   GOES-18 Lat/Lon  NOAA-21 Lat/Lon    Distance(km)  Time Diff(sec)
 06/20/2023   22:39:06   (   0.01,-137.00) (  -0.46,-139.08)  237.66                80
 06/21/2023   22:23:00   (   0.00,-137.00) (   0.52,-134.55)  279.29                80
 06/23/2023   10:42:08   (   0.00,-137.02) (   0.64,-139.82)  319.65                80
 06/24/2023   10:26:03   (   0.01,-137.02) (  -0.41,-135.29)  197.08                80
 06/25/2023   22:45:18   (  -0.01,-137.01) (  -0.81,-140.59)  408.63                80
 06/26/2023   22:29:13   (  -0.01,-137.00) (   0.18,-136.05)  107.72                80
 06/28/2023   10:48:20   (   0.01,-137.01) (   0.98,-141.33)  492.47                80
 06/29/2023   10:32:15   (   0.01,-137.00) (  -0.01,-136.79)   23.45                80
 07/01/2023   22:32:46   (   0.00,-136.96) (  -0.14,-137.57)   69.22                80
 07/02/2023   22:16:40   (   0.00,-136.94) (   0.85,-133.03)  445.62                80