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
2021-03-03 09:04:05 s 1 -162836.80 8 +293278.15 1700.0 C57
2021-03-03 09:14:05 S 09 40 38.714 -09 55 47.96 V C57
2021-03-03 09:14:05 s 1 -163073.93 1 +292856.34 3230.0 C57
2021-03-03 09:20:21 C 09 38 32.87 -09 39 59.9 o 691
2021-03-03 09:24:05 S 09 40 36.360 -09 55 30.18 V C57
2021-03-03 09:24:05 s 1 -163310.43 8 +292433.43 3690.0 C57
2021-03-03 09:34:05 S 09 40 34.037 -09 55 12.76 V C57
2021-03-03 09:34:05 s 1 -163546.32 7 +292009.42 3070.0 C57
2021-03-03 09:42:46 C 09 38 28.30 -09 39 17.1 o 691
2021-03-03 09:44:05 S 09 40 31.680 -09 54 54.22 V C57
2021-03-03 09:44:05 s 1 -163781.59 6 +291584.30 1360.0 C57
2021-03-03 09:54:05 S 09 40 29.323 -09 54 34.45 V C57
2021-03-03 09:54:05 s 1 -164016.24 3 +291158.08 8550.0 C57
2021-03-03 10:02:54 C 09 38 24.23 -09 38 38.8 o 691
2021-03-03 10:04:05 S 09 40 26.942 -09 54 16.02 V C57
2021-03-03 10:04:05 s 1 -164250.26 5 +290730.74 4660.0 C57
2021-03-03 10:13:34 C 09 38 24.66 -09 38 09.8 V T08
2021-03-03 10:14:05 S 09 40 24.590 -09 53 58.06 V C57
2021-03-03 10:14:05 s 1 -164483.66 0 +290302.31 9660.0 C57
2021-03-03 10:17:33 C 09 38 23.82 -09 38 02.3 V T08
2021-03-03 10:24:05 S 09 40 22.265 -09 53 40.38 V C57
2021-03-03 10:24:05 s 1 -164716.42 6 +289872.76 3560.0 C57
2021-03-03 10:26:11 C 09 38 21.99 -09 37 46.0 V T08
2021-03-03 10:34:05 S 09 40 19.920 -09 53 21.62 V C57
2021-03-03 10:34:05 s 1 -164948.56 0 +289442.11 6360.0 C57
2021-03-03 10:44:05 S 09 40 17.604 -09 53 02.18 V C57
2021-03-03 10:44:05 s 1 -165180.06 0 +289010.34 8040.0 C57
2021-03-03 10:44:06 C 09 38 18.20 -09 37 12.2 V T08
2021-03-03 10:54:05 S 09 40 15.230 -09 52 43.97 V C57
2021-03-03 10:54:05 s 1 -165410.92 4 +288577.47 8600.0 C57
2021-03-03 11:04:05 S 09 40 12.893 -09 52 26.18 V C57
2021-03-03 11:04:05 s 1 -165641.15 0 +288143.48 8040.0 C57
2021-03-03 11:14:05 S 09 40 10.524 -09 52 08.04 V C57
2021-03-03 11:14:05 s 1 -165870.73 4 +287708.38 6360.0 C57
2021-03-03 11:24:05 S 09 40 08.150 -09 51 49.10 V C57
2021-03-03 11:24:05 s 1 -166099.67 6 +287272.17 3550.0 C57
2021-03-03 11:34:05 S 09 40 05.791 -09 51 29.16 V C57
2021-03-03 11:34:05 s 1 -166327.97 1 +286834.84 9600.0 C57
2021-03-03 11:44:05 S 09 40 03.470 -09 51 11.38 V C57
2021-03-03 11:44:05 s 1 -166555.61 9 +286396.40 4510.0 C57
2021-03-03 11:54:05 S 09 40 01.111 -09 50 53.20 V C57
2021-03-03 11:54:05 s 1 -166782.61 6 +285956.84 8280.0 C57
2021-03-03 12:04:05 S 09 39 58.793 -09 50 34.84 V C57
2021-03-03 12:04:05 s 1 -167008.96 0 +285516.17 900.0 C57
2021-03-03 12:14:05 S 09 39 56.453 -09 50 15.76 V C57
2021-03-03 12:14:05 s 1 -167234.64 9 +285074.38 2370.0 C57
2021-03-03 12:24:05 S 09 39 54.072 -09 49 56.53 V C57
2021-03-03 12:24:05 s 1 -167459.68 1 +284631.46 2680.0 C57
2021-03-03 12:34:05 S 09 39 51.698 -09 49 38.50 V C57
2021-03-03 12:34:05 s 1 -167684.05 2 +284187.43 1820.0 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)