Simultaneous Nadir Overpasses (SNOs) between NOAA-21 and LANDSAT-9
TLE Epoch: 2023 4 12.  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)
 04/12/2023   15:17:59   ( -70.12, 126.63) 04/12/2023   15:18:53  ( -70.12, 126.65)    1.28                54
 04/12/2023   16:08:43   (  70.01, -65.89) 04/12/2023   16:08:20  (  70.02, -65.84)    1.99                23
 04/12/2023   16:59:11   ( -69.18, 102.63) 04/12/2023   16:58:02  ( -69.24, 100.73)   74.97                69
 04/15/2023   07:34:49   ( -70.10,-117.54) 04/15/2023   07:35:20  ( -70.09,-117.50)    1.68                31
 04/15/2023   08:25:33   (  69.98,  49.93) 04/15/2023   08:24:47  (  69.98,  49.99)    2.19                46
 04/17/2023   23:01:02   (  70.43,-169.60) 04/17/2023   23:02:13  (  70.36,-168.86)   28.46                71
 04/17/2023   23:51:38   ( -70.02,  -1.65) 04/17/2023   23:51:47  ( -70.03,  -1.70)    2.13                 9
 04/18/2023   00:42:22   (  69.91, 165.83) 04/18/2023   00:41:14  (  69.92, 165.79)    1.55                68
 04/20/2023   15:17:45   (  70.11, -53.31) 04/20/2023   15:18:42  (  70.10, -53.34)    1.53                57
 04/20/2023   16:08:27   ( -70.01, 114.15) 04/20/2023   16:08:12  ( -69.99, 114.13)    2.61                15
 04/20/2023   16:58:58   (  69.22, -77.38) 04/20/2023   16:57:50  (  69.27, -79.20)   72.01                68
 04/23/2023   07:34:35   (  70.11,  62.47) 04/23/2023   07:35:07  (  70.09,  62.53)    3.21                32
 04/23/2023   08:25:16   ( -69.96,-129.98) 04/23/2023   08:24:37  ( -69.98,-129.99)    1.85                39
 04/25/2023   23:00:49   ( -70.65,  10.11) 04/25/2023   23:01:59  ( -70.49,  11.35)   49.18                70
 04/25/2023   23:51:23   (  70.02, 178.40) 04/25/2023   23:51:32  (  70.04, 178.36)    3.18                 9
 04/26/2023   00:42:05   ( -69.92, -14.14) 04/26/2023   00:41:02  ( -69.94, -14.16)    1.84                63