Simultaneous Nadir Overpasses (SNOs) between NOAA-21 and LANDSAT-9
TLE Epoch: 2023 9 10.  Predictions up to the next  14.0 days:

     Date     Time(NOAA-21) NOAA-21 Lat/Lon Date Time(LANDSAT-9) LANDSAT-9 Lat/Lon    Distance(km)  Time Diff(sec)
 09/11/2023   16:07:47   ( -69.99, 114.15) 09/11/2023   16:08:33  ( -69.97, 114.15)    2.34                46
 09/11/2023   16:58:31   (  69.86, -78.35) 09/11/2023   16:58:00  (  69.86, -78.34)    0.83                31
 09/14/2023   07:34:15   (  70.81,  61.29) 09/14/2023   07:35:22  (  70.69,  63.45)   80.46                67
 09/14/2023   08:24:42   ( -69.94,-130.02) 09/14/2023   08:25:04  ( -69.92,-130.03)    2.54                22
 09/14/2023   09:15:26   (  69.81,  37.48) 09/14/2023   09:14:31  (  69.81,  37.46)    0.56                55
 09/16/2023   23:50:55   (  69.99, 178.36) 09/16/2023   23:52:04  (  70.00, 178.34)    2.07                69
 09/17/2023   00:41:37   ( -69.90, -14.20) 09/17/2023   00:41:34  ( -69.90, -14.18)    0.86                 3
 09/17/2023   01:32:16   (  69.51, 153.68) 09/17/2023   01:31:04  (  69.62, 153.09)   26.10                72
 09/19/2023   16:07:50   (  69.96, -65.84) 09/19/2023   16:08:34  (  69.96, -65.85)    0.93                44
 09/19/2023   16:58:32   ( -69.88, 101.61) 09/19/2023   16:58:04  ( -69.85, 101.64)    2.72                28
 09/22/2023   07:34:15   ( -70.85,-118.78) 09/22/2023   07:35:22  ( -70.76,-116.43)   86.45                67
 09/22/2023   08:24:44   (  69.95,  49.95) 09/22/2023   08:25:02  (  69.93,  50.01)    2.43                18
 09/22/2023   09:15:25   ( -69.80,-142.51) 09/22/2023   09:14:33  ( -69.78,-142.57)    3.47                52