99942 Apophis (2004 MN4)

NEO PHA MOID ⇩ IMP ⇩ COV ★ EPH ⇩ OBS ⇩ Radar
Orbital Elements
Epoch (TDB)2025-11-21 (JD 2461000.5)
Eccentricity (e)0.1911663196 ± 2.00e+00
Semi-major axis (a)0.9223804710 AU ± 3.00e+00
Inclination (i)3.34095673° ± 4.00e+00
Long. of Asc. Node (Ω)203.89962943° ± 5.00e+00
Arg. of Perihelion (ω)126.67282559° ± 6.00e+00
Mean Anomaly (M)312.80548085° ± 2.46e-06
Mean Motion (n)1.1126206784°/day ± 5.43e+00
Perihelion dist (q)0.74605239 AU ± 3.05e+00
Aphelion dist (Q)1.09870855 AU ± 4.02e+00
Orbital Period0.88586012 yr ± 4.32e+00
NGA Modelr2
A1-3.03172826e-03 AU/d²
A2-2.37461812e-06 AU/d²
Physical Parameters
H (abs. magnitude)19.00
G (slope)0.15
Orbit Solution
SourceIAA
Solution Date2026-04-29
RMS Residual0.213″
Uncertainty0
Orbit TypeAten
MOID0.000007 AU
Observations Used8720
Oppositions2
Arc Total2004-2021
First Observation Used2004-03-15
Last Observation Used2021-05-20
Observations (10797)
Date Type RA Dec Mag Band Observatory
2021-03-06 21:40:31 C 09 22 53.35 -06 56 59.6 q L47
2021-03-06 21:41:33 C 09 22 53.29 -06 56 57.0 q L47
2021-03-06 21:42:33 C 09 22 53.07 -06 56 54.5 q L47
2021-03-06 21:43:24 C 09 22 52.86 -06 56 55.8 q L47
2021-03-06 21:44:15 C 09 22 52.83 -06 56 50.7 q L47
2021-03-06 22:03:05 C 09 22 47.50 -06 56 16.2 q L76
2021-03-06 22:06:09 C 09 22 46.91 -06 56 10.0 q L76
2021-03-06 22:09:21 C 09 22 46.29 -06 56 03.6 q L76
2021-03-06 22:28:43 C 09 22 44.11 -06 55 23.0 V L39
2021-03-06 22:31:54 C 09 22 43.46 -06 55 16.9 V L39
2021-03-06 22:35:05 C 09 22 42.82 -06 55 10.8 V L39
2021-03-06 22:39:01 C 09 22 42.06 -06 55 02.6 V L39
2021-03-06 22:46:31 C 09 22 40.33 -06 54 44.4 V L54
2021-03-07 00:35:29 C 09 22 25.64 -06 50 19.0 H78
2021-03-07 00:37:00 C 09 22 25.32 -06 50 16.4 H78
2021-03-07 00:42:39 C 09 22 24.20 -06 50 04.8 H78
2021-03-07 00:46:40 C 09 22 23.43 -06 49 57.6 H78
2021-03-07 00:47:20 C 09 22 23.27 -06 49 55.7 H78
2021-03-07 00:50:02 C 09 22 22.75 -06 49 50.1 H78
2021-03-07 00:50:43 C 09 22 22.65 -06 49 49.6 H78
2021-03-07 00:50:56 C 09 22 22.25 -06 50 29.9 V W33
2021-03-07 00:51:22 C 09 22 22.51 -06 49 48.5 H78
2021-03-07 00:52:03 C 09 22 22.43 -06 49 46.6 H78
2021-03-07 00:52:44 C 09 22 21.91 -06 50 26.1 V W33
2021-03-07 00:54:04 C 09 22 21.97 -06 49 42.5 H78
2021-03-07 00:54:32 C 09 22 21.56 -06 50 22.7 V W33
2021-03-07 00:54:44 C 09 22 21.84 -06 49 41.5 H78
2021-03-07 00:55:24 C 09 22 21.73 -06 49 39.8 H78
2021-03-07 00:56:05 C 09 22 21.60 -06 49 38.4 H78
2021-03-07 00:56:22 C 09 22 21.22 -06 50 19.2 V W33
2021-03-07 00:56:45 C 09 22 21.46 -06 49 37.3 H78
2021-03-07 00:57:26 C 09 22 21.34 -06 49 36.0 H78
2021-03-07 00:58:09 C 09 22 20.86 -06 50 15.6 V W33
2021-03-07 00:59:59 C 09 22 20.49 -06 50 11.9 V W33
2021-03-07 01:01:47 C 09 22 20.15 -06 50 08.5 V W33
2021-03-07 01:03:39 C 09 22 19.79 -06 50 04.7 V W33
2021-03-07 01:05:34 C 09 22 19.41 -06 50 01.1 V W33
2021-03-07 01:07:21 C 09 22 19.07 -06 49 57.5 V W33
2021-03-07 01:27:09 C 09 22 13.92 -06 48 32.8 q X33
2021-03-07 01:29:23 C 09 22 13.47 -06 48 28.3 q X33
2021-03-07 01:31:05 C 09 22 08.95 -06 49 19.5 V 204
2021-03-07 01:31:36 C 09 22 13.03 -06 48 24.0 q X33
2021-03-07 01:33:27 C 09 22 12.37 -06 47 39.2 q 834
2021-03-07 01:35:45 C 09 22 08.08 -06 49 09.9 V 204
2021-03-07 01:40:45 C 09 22 07.12 -06 48 59.8 V 204
2021-03-07 02:03:27 C 09 22 06.36 -06 46 39.5 q 834
2021-03-07 02:39:19 C 09 22 01.01 -06 46 55.7 V W33
2021-03-07 02:46:38 C 09 21 59.56 -06 46 41.1 V W33
2021-03-07 02:47:41 C 09 21 59.74 -06 46 47.1 q 726
2021-03-07 02:53:55 C 09 21 58.12 -06 46 26.6 V W33
Radar Observations (50)
Epoch (UTC)ValueSigmaUnitsFreq (MHz)ReceiverTransmitter
2005-01-27 23:31:00 -100849.1434 0.25 Hz 2380 -1 -1
2005-01-29 00:00:00 192028507.13 4 us 2380 -1 -1
2005-01-29 00:00:00 -102512.9059 0.25 Hz 2380 -1 -1
2005-01-30 00:18:00 195808170.79 4.5 us 2380 -1 -1
2005-01-30 00:18:00 -103799.8178 0.15 Hz 2380 -1 -1
2005-08-07 17:07:00 8186.8 0.2 Hz 2380 -1 -1
2006-05-06 12:49:00 -118256.8 0.1 Hz 2380 -1 -1
2012-12-21 11:10:00 57992.443 0.25 Hz 8560 -14 -14
2012-12-22 11:00:00 102682986.05 0.25 us 8560 -14 -14
2012-12-22 11:00:00 57880.25 0.1 Hz 8560 -14 -14
2013-01-03 09:20:00 97449107.61 0.25 us 8560 -14 -14
2013-01-03 09:20:00 36629.285 0.1 Hz 8560 -14 -14
2013-01-03 10:00:00 97439308.71 3 us 8560 -14 -14
2013-01-03 10:50:00 97428425.46 0.25 us 8560 -14 -14
2013-01-05 08:40:00 30404.009 0.2 Hz 8560 -14 -14
2013-01-05 10:40:00 96911591.52 0.25 us 8560 -14 -14
2013-01-05 10:40:00 20031.16 0.1 Hz 8560 -14 -14
2013-01-05 10:50:00 96910218.03 3 us 8560 -14 -14
2013-01-06 08:20:00 26660.815 0.1 Hz 8560 -14 -14
2013-01-06 09:30:00 20775.144 0.1 Hz 8560 -14 -14
2013-01-08 08:10:00 15496.441 0.1 Hz 8560 -14 -14
2013-01-09 08:00:00 96451449.73 0.2 us 8560 -14 -14
2013-01-09 08:00:00 9670.119 0.1 Hz 8560 -14 -14
2013-01-09 09:20:00 2690.401 0.1 Hz 8560 -14 -14
2013-01-10 08:00:00 96472652.72 0.2 us 8560 -14 -14
2013-01-10 08:00:00 2590.857 0.1 Hz 8560 -14 -14
2013-01-10 09:40:00 96473924.8 0.2 us 8560 -14 -14
2013-01-11 07:20:00 -1589.599 0.2 Hz 8560 -14 -14
2013-01-14 08:10:00 97258343.56 0.2 us 8560 -14 -14
2013-01-14 08:10:00 -30561.776 0.1 Hz 8560 -14 -14
2013-01-14 09:50:00 97283037.17 0.2 us 8560 -14 -14
2013-01-15 06:30:00 -30666.291 0.1 Hz 8560 -14 -14
2013-01-16 06:30:00 98086754 1 us 8560 -14 -14
2013-01-16 06:30:00 -39582.277 0.2 Hz 8560 -14 -14
2013-01-16 07:50:00 -46641.384 0.1 Hz 8560 -14 -14
2013-01-17 06:20:00 -47875.142 0.1 Hz 8560 -14 -14
2013-02-18 00:56:00 -76760.475 0.2 Hz 2380 -1 -1
2013-02-18 01:37:00 157906444.15 0.25 us 2380 -1 -1
2013-02-18 01:37:00 -78041.365 0.2 Hz 2380 -1 -1
2013-02-19 01:08:00 -78105.657 0.2 Hz 2380 -1 -1
2013-02-20 00:38:00 -78070.341 0.2 Hz 2380 -1 -1
2013-02-20 01:26:00 163578875.87 0.25 us 2380 -1 -1
2013-02-20 01:26:00 -79560.965 0.2 Hz 2380 -1 -1
2013-02-21 01:04:00 -79697.13 0.2 Hz 2380 -1 -1
2013-03-15 23:59:00 235220855.07 2 us 2380 -1 -1
2013-03-15 23:59:00 -80977.5254 0.238 Hz 2380 -1 -1
2021-03-03 06:40:00 29329.8 0.4 Hz 8560 -14 -14
2021-03-05 07:00:00 112426746.52 1 us 8560 -14 -14
2021-03-08 02:50:00 112625015.08 1 us 8560 -14 -14
2021-03-11 08:20:00 113796393.86 1 us 8560 -14 -14
Station codes
-14 DSS-14 Goldstone (70-m) -1 Arecibo (305-m, 1963–2020)