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18646 (1998 ED21)
Classification: Main-belt Asteroid          SPK-ID: 2018646
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]

[ show orbit diagram ]
Orbital Elements at Epoch 2459200.5 (2020-Dec-17.0) TDB
Reference: JPL 29 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1064162599787187 2.9418e-08  
a 2.361981328783332 8.2814e-09 au
q 2.110628109634646 6.8455e-08 au
i 8.886727180049855 4.3466e-06 deg
node 157.298704429422 2.1498e-05 deg
peri 295.9198655565114 3.1081e-05 deg
M 155.4947275535741 2.1531e-05 deg
tp 2458627.801185377295
(2019-May-24.30118538)
7.8901e-05 TDB
period 1325.907164235775
3.63
6.9732e-06
1.909e-08
d
yr
n .2715122217530942 1.4279e-09 deg/d
Q 2.613334547932018 9.1626e-09 au
  Orbit Determination Parameters
   # obs. used (total)      1437  
   data-arc span      12202 days (33.41 yr)  
   first obs. used      1987-02-23  
   last obs. used      2020-07-21  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .5225  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Nov-13 02:13:44  

Additional Information
 Earth MOID = 1.14418 au 
 Jupiter MOID = 2.53326 au 
 T_jup = 3.527 
[ show covariance matrix ]

Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]

Physical Parameter Table
Parameter Symbol Value Units Sigma Reference Notes
absolute magnitude H 14.8   n/a MPO467912  
diameter diameter 4.386 km 0.163 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  
geometric albedo albedo 0.084   0.011 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  

18646 (1998 ED21)          Discovered 1998-Mar-03 by Elst, E. W. at La Silla
Reference: 20001111/Numbers.arcLast Updated: 2004-04-19

Alternate Designations
 1998 ED21 = 1987 DD3 = 1996 RS2 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
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