Simultaneous Nadir Overpasses (SNOs) between NOAA-21 and LANDSAT-9
TLE Epoch: 2023 5 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)
 05/11/2023   23:00:54   ( -70.55,  10.20) 05/11/2023   23:02:04  ( -70.44,  11.22)   39.87                70
 05/11/2023   23:51:31   (  70.06, 178.28) 05/11/2023   23:51:36  (  70.07, 178.33)    2.19                 5
 05/12/2023   00:42:12   ( -69.93, -14.20) 05/12/2023   00:41:06  ( -69.95, -14.21)    2.90                66
 05/14/2023   15:17:42   ( -70.11, 126.65) 05/14/2023   15:18:38  ( -70.11, 126.61)    1.75                56
 05/14/2023   16:08:26   (  69.99, -65.86) 05/14/2023   16:08:05  (  70.00, -65.89)    2.02                21
 05/14/2023   16:58:55   ( -69.22, 102.58) 05/14/2023   16:57:46  ( -69.28, 100.77)   72.01                69
 05/17/2023   07:34:37   ( -70.05,-117.50) 05/17/2023   07:35:06  ( -70.06,-117.57)    2.97                29
 05/17/2023   08:25:22   (  69.98,  49.92) 05/17/2023   08:24:33  (  69.95,  49.92)    3.26                49
 05/19/2023   23:00:52   (  70.20,-169.27) 05/19/2023   23:02:02  (  70.20,-169.12)    5.65                70
 05/19/2023   23:51:33   ( -70.06,  -1.74) 05/19/2023   23:51:33  ( -70.04,  -1.72)    1.96                 0
 05/20/2023   00:42:13   (  69.78, 165.99) 05/20/2023   00:41:01  (  69.82, 165.61)   15.01                72
 05/22/2023   15:17:45   (  70.11, -53.37) 05/22/2023   15:18:29  (  70.09, -53.40)    2.55                44
 05/22/2023   16:08:27   ( -70.02, 114.09) 05/22/2023   16:07:58  ( -70.04, 114.16)    3.49                29
 05/25/2023   06:44:09   ( -70.87,-106.13) 05/25/2023   06:45:17  ( -70.76,-104.17)   72.87                68
 05/25/2023   07:34:40   (  70.08,  62.44) 05/25/2023   07:34:54  (  70.10,  62.51)    3.52                14
 05/25/2023   08:25:21   ( -69.93,-130.02) 05/25/2023   08:24:25  ( -69.94,-130.08)    2.53                56