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
2021-02-18 07:12:55 C 10 37 50.31 -17 11 56.8 o 691
2021-02-18 20:32:11 C 10 35 34.01 -16 58 09.9 V 221
2021-02-18 20:34:09 C 10 35 33.64 -16 58 08.1 V 221
2021-02-18 20:35:55 C 10 35 33.30 -16 58 06.5 V 221
2021-02-18 21:02:13 C 10 35 28.33 -16 57 42.4 V 221
2021-02-18 21:04:09 C 10 35 27.97 -16 57 40.5 V 221
2021-02-18 21:05:55 C 10 35 27.61 -16 57 38.8 V 221
2021-02-18 21:32:22 C 10 35 22.57 -16 57 14.3 V 221
2021-02-18 21:34:07 C 10 35 22.21 -16 57 12.5 V 221
2021-02-18 21:35:54 C 10 35 21.89 -16 57 10.9 V 221
2021-02-18 22:07:33 C 10 35 15.80 -16 56 41.1 V 221
2021-02-18 22:09:20 C 10 35 15.45 -16 56 39.3 V 221
2021-02-18 22:11:06 C 10 35 15.12 -16 56 37.7 V 221
2021-02-18 22:24:59 C 10 35 11.83 -16 57 36.3 q 056
2021-02-18 22:38:40 C 10 35 09.76 -16 56 11.3 V 221
2021-02-18 22:40:26 C 10 35 09.41 -16 56 09.5 V 221
2021-02-18 22:42:33 C 10 35 09.02 -16 56 07.5 V 221
2021-02-18 22:49:16 C 10 35 07.25 -16 57 13.2 q 056
2021-02-18 23:12:59 C 10 35 02.77 -16 56 49.6 q 056
2021-02-18 23:17:44 C 10 35 01.86 -16 56 45.0 q 056
2021-02-19 00:05:42 C 10 34 53.93 -16 55 58.9 V Z80
2021-02-19 00:10:42 C 10 34 53.01 -16 55 53.9 V Z80
2021-02-19 00:15:42 C 10 34 52.04 -16 55 49.1 V Z80
2021-02-19 00:20:42 C 10 34 51.12 -16 55 44.0 V Z80
2021-02-19 07:14:58 C 10 33 38.83 -16 48 37.7 V 703
2021-02-19 07:22:42 C 10 33 37.30 -16 48 29.4 V 703
2021-02-19 07:38:08 C 10 33 34.31 -16 48 13.5 V 703
2021-02-19 19:04:05 S 10 32 49.260 -16 56 01.79 V C57
2021-02-19 19:04:05 s 1 -200299.47 1 +186790.13 2790.0 C57
2021-02-19 19:14:05 S 10 32 46.946 -16 55 50.48 V C57
2021-02-19 19:14:05 s 1 -200341.90 8 +186135.76 2050.0 C57
2021-02-19 19:24:05 S 10 32 44.645 -16 55 39.61 V C57
2021-02-19 19:24:05 s 1 -200382.98 1 +185480.11 8770.0 C57
2021-02-19 19:34:05 S 10 32 42.367 -16 55 27.48 V C57
2021-02-19 19:34:05 s 1 -200422.68 4 +184823.19 2950.0 C57
2021-02-19 19:44:05 S 10 32 40.025 -16 55 16.86 V C57
2021-02-19 19:44:05 s 1 -200461.01 0 +184165.00 4570.0 C57
2021-02-19 19:47:53 C 10 31 25.75 -16 35 31.9 V M44
2021-02-19 19:54:05 S 10 32 37.764 -16 55 05.27 V C57
2021-02-19 19:54:05 s 1 -200497.95 3 +183505.52 3610.0 C57
2021-02-19 20:04:05 S 10 32 35.424 -16 54 54.29 V C57
2021-02-19 20:04:05 s 1 -200533.50 5 +182844.77 80.0 C57
2021-02-19 20:06:00 C 10 31 22.10 -16 35 13.7 V M44
2021-02-19 20:14:05 S 10 32 33.163 -16 54 43.31 V C57
2021-02-19 20:14:05 s 1 -200567.66 2 +182182.74 3950.0 C57
2021-02-19 20:24:05 S 10 32 30.799 -16 54 32.26 V C57
2021-02-19 20:24:05 s 1 -200600.41 5 +181519.43 5210.0 C57
2021-02-19 20:27:10 C 10 31 17.93 -16 34 51.1 V M44
2021-02-19 20:34:05 S 10 32 28.502 -16 54 21.46 V C57
2021-02-19 20:34:05 s 1 -200631.75 8 +180854.83 3840.0 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)