Simultaneous Nadir Overpasses (SNOs) between NOAA-21 and LANDSAT-9
TLE Epoch: 2023 5 1.  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)
 05/01/2023   07:34:29   ( -70.10,-117.51) 05/01/2023   07:35:12  ( -70.11,-117.49)    1.11                43
 05/01/2023   08:25:13   (  69.98,  49.99) 05/01/2023   08:24:40  (  69.96,  49.94)    3.15                33
 05/03/2023   23:00:53   (  70.66,-169.94) 05/03/2023   23:02:02  (  70.54,-168.61)   50.82                69
 05/03/2023   23:51:25   ( -70.05,  -1.66) 05/03/2023   23:51:39  ( -70.04,  -1.71)    1.77                14
 05/04/2023   00:42:09   (  69.92, 165.83) 05/04/2023   00:41:06  (  69.93, 165.79)    1.96                63
 05/06/2023   15:17:40   (  70.14, -53.36) 05/06/2023   15:18:35  (  70.11, -53.35)    3.26                55
 05/06/2023   16:08:21   ( -70.00, 114.17) 05/06/2023   16:08:05  ( -69.99, 114.12)    1.91                16
 05/06/2023   16:58:52   (  69.18, -77.34) 05/06/2023   16:57:44  (  69.22, -79.28)   76.65                68
 05/09/2023   07:34:36   (  70.10,  62.46) 05/09/2023   07:35:00  (  70.09,  62.51)    2.27                24
 05/09/2023   08:25:17   ( -69.96,-130.01) 05/09/2023   08:24:30  ( -69.98,-130.01)    2.36                47
 05/11/2023   23:00:46   ( -70.13,  10.86) 05/11/2023   23:01:57  ( -70.15,  10.85)    2.74                71
 05/11/2023   23:51:30   (  70.01, 178.35) 05/11/2023   23:51:24  (  70.04, 178.34)    2.88                 6
 05/12/2023   00:42:09   ( -69.76, -13.96) 05/12/2023   00:40:56  ( -69.82, -14.34)   15.76                73
 05/14/2023   15:17:42   ( -70.10, 126.66) 05/14/2023   15:18:22  ( -70.08, 126.64)    2.54                40
 05/14/2023   16:08:26   (  69.99, -65.86) 05/14/2023   16:07:49  (  69.96, -65.87)    3.02                37