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21000 L'Encyclopedie (1987 BY1)
Classification: Main-belt Asteroid          SPK-ID: 2021000
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

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Orbit Diagram
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Note: This Java-based orbit viewer will eventually be retired.

Note: Make sure you have Java enabled on your browser to see the applet. This applet is provided as a 3D orbit visualization tool. The applet 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. For accurate long-term ephemerides, please instead use our Horizons system.

Note: If the applet is not working, here are some notes that might help.
Orbit Viewer

Additional Notes: the orbits shown in the applet are color coded. The planets are white lines, and the asteroid/comet is a blue line. The bright white line indicates the portion of the orbit that is above the ecliptic plane, and the darker portion is below the ecliptic plane. Likewise for the asteroid/comet orbit, the light blue indicates the portion above the ecliptic plane, and the dark blue the portion below the ecliptic plane.

Orbit Viewer applet originally written and kindly provided by Osamu Ajiki (AstroArts), and further modified by Ron Baalke (JPL).

Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB
Reference: JPL 24 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .2316627067466424 3.1791e-08  
a 2.558285481240075 1.1191e-08 au
q 1.965626142025363 7.769e-08 au
i 12.93443197238586 5.6022e-06 deg
node 136.1653876409773 3.0683e-05 deg
peri 328.8337276693646 3.7096e-05 deg
M 67.2465196660942 1.9821e-05 deg
tp 2458721.316821290072
8.2003e-05 TDB
period 1494.589531690655
n .2408688087041356 1.5805e-09 deg/d
Q 3.150944820454787 1.3784e-08 au
  Orbit Determination Parameters
   # obs. used (total)      1141  
   data-arc span      12196 days (33.39 yr)  
   first obs. used      1987-01-26  
   last obs. used      2020-06-17  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .51959  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Nov-13 01:59:29  

Additional Information
 Earth MOID = .993162 au 
 Jupiter MOID = 2.01461 au 
 T_jup = 3.364 
[ show covariance matrix ]

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 15.0   n/a MPO384934  
diameter diameter 5.886 km 0.275 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (  
geometric albedo albedo 0.067   0.022 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (  

21000 L´Encyclopédie           Discovered 1987 Jan. 26 by E. W. Elst at the European Southern Observatory.
The Encyclopédie or Dictionnaire raisonné des sciences, des arts et des métiers (1751-1772), by Diderot and d´Alembert, may be considered the principal work of the Age of Enlightenment.
NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character)
Reference: 20030106/MPCPages.arcLast Updated: 2003-10-02

[ show close-approach data ]
Alternate Designations
 1987 BY1 = 2000 JS79 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
FirstGov 2020-Nov-27 01:04 UT
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