| 99942 Apophis (2004 MN4) |
| Classification: Aten [NEO, PHA] SPK-ID: 2099942 |
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For accurate long-term ephemerides, please instead use our Horizons system.This orbit viewer was implemented using two-body methods, and hence should not be used for determining accurate long-term trajectories (over several years or decades) or planetary encounter circumstances.
Orbital Elements at Epoch 2459200.5 (2020-Dec-17.0) TDB
Reference: JPL 214 (heliocentric ecliptic J2000)
| Element | Value | Uncertainty (1-sigma) | Units |
| e | .1915088679188845 | 1.237e-09 | |
| a | .922524711665536 | 1.7637e-09 | au |
| q | .7458530485072739 | 2.4352e-09 | au |
| i | 3.336773207452075 | 9.8177e-08 | deg |
| node | 204.0419938887713 | 2.4246e-06 | deg |
| peri | 126.6539581877261 | 2.6314e-06 | deg |
| M | 110.6321810561187 | 5.569e-07 | deg |
| tp | 2459101.040925624416
(2020-Sep-08.54092562) | 5.2995e-07 | TDB |
| period | 323.6424197137346
0.89 | 9.281e-07
2.541e-09 | d
yr |
| n | 1.112338735813507 | 3.1898e-09 | deg/d |
| Q | 1.099196374823798 | 2.1014e-09 | au |
|
Additional Model Parameters
| Parameter | Value | Uncertainty (1-sigma) |
| A1 [EST] | 3.869430936996365E-13 | 4.859E-13 |
| A2 [EST] | -2.898628980466162E-14 | 1.74E-16 |
| ALN [SET] | 1. | n/a |
| NK [SET] | 0. | n/a |
| NM [SET] | 2. | n/a |
| R0 [SET] | 1. | n/a |
|
| | Orbit Determination Parameters
Additional Information
|
[ hide covariance matrix ]
Orbital Elements at Epoch 2459311.5 (2021-Apr-07.0) TDB
Reference: JPL 214 (heliocentric ecliptic J2000)
| Element | Value | Uncertainty (1-sigma) | Units |
| e | .1915350975906659 | 1.4353e-09 | |
| q | .7458351838564465 | 2.581e-09 | au |
| tp | 2459424.583935278725
(2021-Jul-29.08393528) | 5.3409e-07 | TDB |
| node | 203.9782743995174 | 2.4205e-06 | deg |
| peri | 126.6377455281965 | 2.7902e-06 | deg |
| i | 3.33973556589891 | 9.8254e-08 | deg |
|
Additional Model Parameters
| Parameter | Value | Uncertainty (1-sigma) |
| A1 [EST] | 3.869430936996365E-13 | 4.859E-13 |
| A2 [EST] | -2.898628980466162E-14 | 1.74E-16 |
| ALN [SET] | 1. | n/a |
| NK [SET] | 0. | n/a |
| NM [SET] | 2. | n/a |
| R0 [SET] | 1. | n/a |
|
| | Orbit Determination Parameters
Additional Information
|
Orbit Covariance (8×8)
|
| |
e |
q |
tp |
node |
peri |
i |
A1 |
A2 |
| e |
2.060111532334871E-18 |
-3.565438164058995E-18 |
5.41378067283879E-16 |
-8.181602025480878E-16 |
1.73576626380241E-15 |
9.381890961591728E-17 |
5.900374542505727E-22 |
-8.07059982990185E-26 |
| q |
-3.565438164058995E-18 |
6.661366314390095E-18 |
-8.168839558369913E-16 |
1.407959641401089E-15 |
-2.959746430237829E-15 |
-1.847985628581548E-16 |
-1.20243013686256E-21 |
1.26323009286461E-25 |
| tp |
5.41378067283879E-16 |
-8.168839558369913E-16 |
2.852480919730787E-13 |
-7.666705947204411E-13 |
1.100374403908294E-12 |
4.011425074072654E-14 |
1.104324427151457E-19 |
-3.667450616812088E-23 |
| node |
-8.181602025480878E-16 |
1.407959641401089E-15 |
-7.666705947204411E-13 |
5.858885831261472E-12 |
-6.582211791700421E-12 |
-1.583193777558196E-13 |
-2.300545537252517E-19 |
1.273940496494377E-22 |
| peri |
1.73576626380241E-15 |
-2.959746430237829E-15 |
1.100374403908294E-12 |
-6.582211791700421E-12 |
7.784945125870097E-12 |
2.146381332524364E-13 |
4.786624628770449E-19 |
-1.765142906156577E-22 |
| i |
9.381890961591728E-17 |
-1.847985628581548E-16 |
4.011425074072654E-14 |
-1.583193777558196E-13 |
2.146381332524364E-13 |
9.653854062018893E-15 |
3.501428998143433E-20 |
-5.731555689028238E-24 |
| A1 |
5.900374542505727E-22 |
-1.20243013686256E-21 |
1.104324427151457E-19 |
-2.300545537252517E-19 |
4.786624628770449E-19 |
3.501428998143433E-20 |
2.360776939350411E-25 |
-1.654012539189738E-29 |
| A2 |
-8.07059982990185E-26 |
1.26323009286461E-25 |
-3.667450616812088E-23 |
1.273940496494377E-22 |
-1.765142906156577E-22 |
-5.731555689028238E-24 |
-1.654012539189738E-29 |
3.028035520350696E-32 |
|
Physical Parameter Table
| Parameter |
Symbol |
Value |
Units |
Sigma |
Reference |
Notes |
| absolute magnitude |
H |
19.7 |
|
0.4 |
Delbo, Cellino and Tedesco (Icarus 2007) |
|
| magnitude slope |
G |
0.25 |
|
n/a |
Delbo, Cellino and Tedesco (Icarus 2007) |
based on taxonomic type (Bowell et al., Asteroids II) |
| diameter |
diameter |
0.34 |
km |
0.04 |
Brozovic et al. (2018) |
Based on 3D shape model derived from radar observations in 2012-2013 |
| rotation period |
rot_per |
30.4 |
h |
n/a |
Behrend (2005) |
combined light-curve on-line at http://obswww.unige.ch/~behrend/r099942a.png |
| geometric albedo |
albedo |
0.23 |
|
n/a |
T. Mueller (2013) |
http://www.esa.int/Our_Activities/Space_Science/Herschel_intercepts_asteroid_Apophis |
| SMASSII spectral type |
spec_B |
Sq |
|
n/a |
Binzel, R. P. et al. Icarus 200 (2009) 480-485 |
|
|
| 99942 Apophis | Discovered 2004 June 19 by R. A. Tucker, D. J. Tholen and F. Bernardi at Kitt Peak. |
| Also known as Apep, the Destroyer, Apophis is the Egyptian god of evil and destruction who dwelled in eternal darkness. As a result of its passage within 40~000 km of the earth on 2029 Apr. 13, this minor planet will move from the Aten to the Apollo class. |
| NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character) |
| Reference: 20050721/MPCPages.arc | Last Updated: 2005-07-21 |
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