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99942 Apophis (2004 MN4)
Classification: Aten [NEO, PHA]          SPK-ID: 2099942
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

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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.

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Orbital Elements at Epoch 2454733.5 (2008-Sep-24.0) TDB
Reference: JPL 199 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1911953048308701 5.3461e-09  
a .9224383019077086 4.1547e-10 au
q .7460724295867941 4.7439e-09 au
i 3.331369520013644 3.5025e-07 deg
node 204.4460289189818 2.1065e-05 deg
peri 126.401879524849 2.0643e-05 deg
M 180.429373045644 5.4642e-06 deg
tp 2454894.912519503203
5.0014e-06 TDB
period 323.596949048484
n 1.112495037603281 7.5161e-10 deg/d
Q 1.098804174228623 4.9491e-10 au

Additional Model Parameters
 Parameter Value Uncertainty (1-sigma) 
A2 [EST] -5.592840054057059E-14 2.201E-14
ALN [SET] 1. n/a
NK [SET] 0. n/a
NM [SET] 2. n/a
R0 [SET] 1. n/a
  Orbit Determination Parameters
   # obs. used (total)      4481  
   # delay obs. used      17  
   # Doppler obs. used      29  
   data-arc span      3946 days (10.80 yr)  
   first obs. used      2004-03-15  
   last obs. used      2015-01-03  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .2745  
   source      ORB  
   producer      Giorgini  
   solution date      2017-Aug-09 01:08:15  

Additional Information
 Earth MOID = .000315683 au 
 Jupiter MOID = 4.12582 au 
 T_jup = 6.466 
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Orbit Covariance (7×7)
  e q tp node peri i A2
e 2.858062040774483E-17 -2.531903029559859E-17 2.451271598753632E-14 5.341143529000106E-14 -5.064059304794175E-14 -2.316088496620918E-16 -9.159706240530915E-23
q -2.531903029559859E-17 2.250437378457998E-17 -2.122266051203493E-14 -5.100944859184798E-14 4.826834522209508E-14 2.76636664162405E-16 7.744081722922498E-23
tp 2.451271598753632E-14 -2.122266051203493E-14 2.501437350446983E-11 1.16213242311946E-11 -1.057653022558682E-11 4.597741246907787E-13 -1.026132427113056E-19
node 5.341143529000106E-14 -5.100944859184798E-14 1.16213242311946E-11 4.437388022822618E-10 -4.338840441053813E-10 -6.817498150073878E-12 -4.324000765783613E-21
peri -5.064059304794175E-14 4.826834522209508E-14 -1.057653022558682E-11 -4.338840441053813E-10 4.261149273549589E-10 6.697032883689781E-12 1.139615135464918E-20
i -2.316088496620918E-16 2.76636664162405E-16 4.597741246907787E-13 -6.817498150073878E-12 6.697032883689781E-12 1.22672053287042E-13 -2.524941685627351E-21
A2 -9.159706240530915E-23 7.744081722922498E-23 -1.026132427113056E-19 -4.324000765783613E-21 1.139615135464918E-20 -2.524941685627351E-21 4.846398125111792E-28

Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

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
geometric albedo albedo 0.23   n/a T. Mueller (2013)
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.arcLast Updated: 2005-07-21

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