Simultaneous Nadir Overpasses (SNOs) between NOAA-21 and LANDSAT-9
TLE Epoch: 2023 5 4.  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)
 05/06/2023   15:17:40   (  70.11, -53.33) 05/06/2023   15:18:35  (  70.13, -53.32)    2.14                55
 05/06/2023   16:08:22   ( -70.03, 114.12) 05/06/2023   16:08:05  ( -70.02, 114.15)    2.23                17
 05/06/2023   16:58:52   (  69.16, -77.31) 05/06/2023   16:57:44  (  69.25, -79.24)   76.94                68
 05/09/2023   07:34:35   (  70.08,  62.49) 05/09/2023   07:35:00  (  70.06,  62.47)    1.53                25
 05/09/2023   08:25:16   ( -69.94,-129.98) 05/09/2023   08:24:30  ( -69.95,-130.05)    3.06                46
 05/11/2023   23:00:47   ( -70.16,  10.81) 05/11/2023   23:01:58  ( -70.13,  10.82)    3.39                71
 05/11/2023   23:51:31   (  70.04, 178.30) 05/11/2023   23:51:25  (  70.02, 178.31)    2.44                 6
 05/12/2023   00:42:09   ( -69.74, -13.93) 05/12/2023   00:40:57  ( -69.80, -14.37)   17.86                72
 05/14/2023   15:17:42   ( -70.08, 126.69) 05/14/2023   15:18:23  ( -70.07, 126.62)    3.19                41
 05/14/2023   16:08:26   (  69.97, -65.82) 05/14/2023   16:07:50  (  69.95, -65.89)    3.02                36
 05/17/2023   06:44:02   (  70.47,  74.53) 05/17/2023   06:45:13  (  70.36,  75.30)   31.53                71
 05/17/2023   07:34:38   ( -70.06,-117.51) 05/17/2023   07:34:47  ( -70.03,-117.53)    3.34                 9
 05/17/2023   08:25:22   (  69.95,  49.97) 05/17/2023   08:24:13  (  69.97,  50.03)    3.42                69