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
2021-02-19 22:44:05 s 1 -200907.80 3 +172097.92 1620.0 C57
2021-02-19 22:44:38 C 10 30 53.54 -16 32 41.9 L28
2021-02-19 22:47:51 C 10 30 52.95 -16 32 38.7 L28
2021-02-19 22:49:59 C 10 30 52.54 -16 32 36.8 L28
2021-02-19 22:52:07 C 10 30 52.10 -16 32 34.4 L28
2021-02-19 22:54:05 S 10 31 56.210 -16 51 43.24 V C57
2021-02-19 22:54:05 s 1 -200918.68 1 +171415.25 2170.0 C57
2021-02-19 22:54:14 C 10 30 51.66 -16 32 31.9 L28
2021-02-19 22:56:22 C 10 30 51.26 -16 32 29.8 L28
2021-02-19 22:58:30 C 10 30 50.81 -16 32 28.0 L28
2021-02-19 23:00:38 C 10 30 50.40 -16 32 25.8 L28
2021-02-19 23:04:05 S 10 31 53.902 -16 51 31.50 V C57
2021-02-19 23:04:05 s 1 -200928.04 2 +170731.29 9890.0 C57
2021-02-19 23:04:55 C 10 30 49.56 -16 32 21.3 L28
2021-02-19 23:10:35 C 10 30 49.766 -16 32 07.22 V Z84
2021-02-19 23:14:05 S 10 31 51.600 -16 51 20.27 V C57
2021-02-19 23:14:05 s 1 -200935.88 1 +170046.03 4780.0 C57
2021-02-19 23:14:30 C 10 30 47.72 -16 32 10.7 L28
2021-02-19 23:21:59 C 10 30 46.28 -16 32 02.8 L28
2021-02-19 23:24:05 S 10 31 49.349 -16 51 08.93 V C57
2021-02-19 23:24:05 s 1 -200942.18 8 +169359.47 6810.0 C57
2021-02-19 23:34:05 S 10 31 46.973 -16 50 57.95 V C57
2021-02-19 23:34:05 s 1 -200946.95 8 +168671.60 5980.0 C57
2021-02-19 23:40:10 C 10 30 41.63 -16 31 41.7 c 095
2021-02-19 23:41:16 C 10 30 41.38 -16 31 40.5 c 095
2021-02-19 23:42:06 C 10 30 41.21 -16 31 39.0 c 095
2021-02-19 23:42:24 C 10 30 41.13 -16 31 38.7 c 095
2021-02-19 23:43:14 C 10 30 41.00 -16 31 38.2 c 095
2021-02-19 23:43:30 C 10 30 40.95 -16 31 38.2 c 095
2021-02-19 23:44:05 S 10 31 44.614 -16 50 46.07 V C57
2021-02-19 23:44:05 s 1 -200950.18 1 +167982.44 2270.0 C57
2021-02-19 23:54:05 S 10 31 42.283 -16 50 34.66 V C57
2021-02-19 23:54:05 s 1 -200951.85 0 +167291.96 5650.0 C57
2021-02-20 00:04:05 S 10 31 39.984 -16 50 23.68 V C57
2021-02-20 00:04:05 s 1 -200951.95 7 +166600.19 6130.0 C57
2021-02-20 00:10:18 C 10 30 38.073 -16 31 04.45 V Z84
2021-02-20 00:14:05 S 10 31 37.670 -16 50 11.18 V C57
2021-02-20 00:14:05 s 1 -200950.49 6 +165907.10 3680.0 C57
2021-02-20 00:24:05 S 10 31 35.359 -16 49 59.95 V C57
2021-02-20 00:24:05 s 1 -200947.45 7 +165212.71 8290.0 C57
2021-02-20 00:34:05 S 10 31 33.038 -16 49 48.50 V C57
2021-02-20 00:34:05 s 1 -200942.83 3 +164517.01 9950.0 C57
2021-02-20 00:44:05 S 10 31 30.691 -16 49 36.88 V C57
2021-02-20 00:44:05 s 1 -200936.61 6 +163820.00 8630.0 C57
2021-02-20 00:54:05 S 10 31 28.008 -16 49 26.94 V C57
2021-02-20 00:54:05 s 1 -200928.79 8 +163121.68 4320.0 C57
2021-02-20 01:04:05 S 10 31 26.076 -16 49 15.02 V C57
2021-02-20 01:04:05 s 1 -200919.37 0 +162422.05 7020.0 C57
2021-02-20 01:10:36 C 10 30 26.226 -16 29 59.98 V Z84
2021-02-20 01:14:05 S 10 31 23.777 -16 49 02.14 V C57
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)