Simultaneous Nadir Overpasses (SNOs) between NOAA-21 and LANDSAT-9
TLE Epoch: 2023 9 11.  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   ( -69.97, 114.17) 09/11/2023   16:08:33  ( -69.98, 114.17)    0.65                46
 09/11/2023   16:58:31   (  69.84, -78.33) 09/11/2023   16:58:01  (  69.82, -78.40)    3.37                30
 09/14/2023   07:34:15   (  70.80,  61.32) 09/14/2023   07:35:22  (  70.70,  63.47)   79.86                67
 09/14/2023   08:24:42   ( -69.93,-130.00) 09/14/2023   08:25:04  ( -69.93,-130.01)    0.94                22
 09/14/2023   09:15:26   (  69.80,  37.50) 09/14/2023   09:14:31  (  69.83,  37.49)    3.22                55
 09/16/2023   23:50:56   (  70.02, 178.31) 09/16/2023   23:52:04  (  70.02, 178.36)    1.97                68
 09/17/2023   00:41:37   ( -69.89, -14.17) 09/17/2023   00:41:34  ( -69.91, -14.16)    2.86                 3
 09/17/2023   01:32:17   (  69.55, 153.63) 09/17/2023   01:31:05  (  69.58, 153.03)   23.63                72
 09/19/2023   16:07:49   (  69.94, -65.80) 09/19/2023   16:08:33  (  69.97, -65.83)    3.13                44
 09/19/2023   16:58:31   ( -69.85, 101.64) 09/19/2023   16:58:03  ( -69.86, 101.66)    1.14                28
 09/22/2023   07:34:16   ( -70.87,-118.82) 09/22/2023   07:35:22  ( -70.77,-116.42)   88.69                66
 09/22/2023   08:24:44   (  69.92,  49.99) 09/22/2023   08:25:02  (  69.94,  50.02)    2.78                18
 09/22/2023   09:15:26   ( -69.83,-142.55) 09/22/2023   09:14:32  ( -69.84,-142.49)    2.90                54
 09/24/2023   23:50:55   ( -70.02,  -1.70) 09/24/2023   23:52:04  ( -70.01,  -1.64)    2.34                69
 09/25/2023   00:41:39   (  69.91, 165.78) 09/25/2023   00:41:31  (  69.89, 165.84)    2.76                 8
 09/25/2023   01:32:17   ( -69.60, -26.45) 09/25/2023   01:31:04  ( -69.63, -26.89)   17.34                73