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
2021-03-04 18:54:05 S 09 32 40.291 -08 51 07.06 V C57
2021-03-04 18:54:05 s 1 -194336.19 5 +183650.11 6460.0 C57
2021-03-04 18:57:10 C 09 32 16.35 -08 36 19.0 V A84
2021-03-04 18:58:59 C 09 32 15.98 -08 36 15.6 V A84
2021-03-04 19:00:50 C 09 32 15.61 -08 36 12.1 V A84
2021-03-04 19:02:39 C 09 32 15.24 -08 36 08.6 V A84
2021-03-04 19:04:05 S 09 32 37.913 -08 50 47.83 V C57
2021-03-04 19:04:05 s 1 -194381.92 2 +182982.53 2610.0 C57
2021-03-04 19:04:28 C 09 32 14.86 -08 36 05.1 V A84
2021-03-04 19:06:18 C 09 32 14.49 -08 36 01.6 V A84
2021-03-04 19:08:08 C 09 32 14.12 -08 35 58.1 V A84
2021-03-04 19:09:58 C 09 32 13.75 -08 35 54.7 V A84
2021-03-04 19:11:47 C 09 32 13.37 -08 35 51.1 V A84
2021-03-04 19:13:37 C 09 32 13.00 -08 35 47.7 V A84
2021-03-04 19:14:05 S 09 32 35.537 -08 50 28.07 V C57
2021-03-04 19:14:05 s 1 -194426.22 2 +182313.61 6130.0 C57
2021-03-04 19:15:27 C 09 32 12.62 -08 35 44.2 V A84
2021-03-04 19:17:17 C 09 32 12.25 -08 35 40.7 V A84
2021-03-04 19:19:06 C 09 32 11.88 -08 35 37.2 V A84
2021-03-04 19:20:57 C 09 32 11.50 -08 35 33.7 V A84
2021-03-04 19:22:46 C 09 32 11.13 -08 35 30.2 V A84
2021-03-04 19:24:05 S 09 32 33.209 -08 50 06.65 V C57
2021-03-04 19:24:05 s 1 -194469.09 0 +181643.35 7010.0 C57
2021-03-04 19:24:35 C 09 32 10.76 -08 35 26.7 V A84
2021-03-04 19:26:25 C 09 32 10.38 -08 35 23.3 V A84
2021-03-04 19:28:15 C 09 32 10.01 -08 35 19.7 V A84
2021-03-04 19:30:05 C 09 32 09.64 -08 35 16.2 V A84
2021-03-04 19:31:54 C 09 32 09.26 -08 35 12.7 V A84
2021-03-04 19:32:45 C 09 32 09.90 -08 35 13.7 q K73
2021-03-04 19:34:05 S 09 32 30.806 -08 49 46.96 V C57
2021-03-04 19:34:05 s 1 -194510.51 6 +180971.75 5230.0 C57
2021-03-04 19:38:07 C 09 32 08.80 -08 35 03.7 q K73
2021-03-04 19:41:40 C 09 32 07.25 -08 34 53.9 V A84
2021-03-04 19:43:30 C 09 32 06.87 -08 34 50.4 V A84
2021-03-04 19:44:05 S 09 32 28.423 -08 49 27.59 V C57
2021-03-04 19:44:05 s 1 -194550.49 5 +180298.81 790.0 C57
2021-03-04 19:45:20 C 09 32 06.50 -08 34 46.9 V A84
2021-03-04 19:45:25 C 09 32 07.32 -08 34 49.4 q K73
2021-03-04 19:47:09 C 09 32 06.13 -08 34 43.4 V A84
2021-03-04 19:48:59 C 09 32 05.74 -08 34 39.9 V A84
2021-03-04 19:50:49 C 09 32 05.37 -08 34 36.4 V A84
2021-03-04 19:52:39 C 09 32 04.99 -08 34 32.9 V A84
2021-03-04 19:54:05 S 09 32 26.059 -08 49 07.43 V C57
2021-03-04 19:54:05 s 1 -194589.02 0 +179624.52 3660.0 C57
2021-03-04 19:54:28 C 09 32 04.62 -08 34 29.4 V A84
2021-03-04 19:56:18 C 09 32 04.24 -08 34 25.9 V A84
2021-03-04 19:58:08 C 09 32 03.87 -08 34 22.4 V A84
2021-03-04 19:59:57 C 09 32 03.49 -08 34 18.9 V A84
2021-03-04 20:01:47 C 09 32 03.12 -08 34 15.4 V A84
2021-03-04 20:03:37 C 09 32 02.74 -08 34 11.9 V A84
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)