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18499 Showalter (1996 MR)
Classification: Mars-crossing Asteroid          SPK-ID: 2018499
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.


Orbital Elements at Epoch 2459200.5 (2020-Dec-17.0) TDB
Reference: JPL 16 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .3497658346772667 3.8362e-08  
a 2.39178338842746 1.0244e-08 au
q 1.555219275206908 9.2341e-08 au
i 4.285569867899149 4.5104e-06 deg
node 134.6097375832992 5.7197e-05 deg
peri 193.3703343467704 5.7764e-05 deg
M 212.1150657508038 1.3162e-05 deg
tp 2459755.512323854654
(2022-Jun-25.01232385)
5.2484e-05 TDB
period 1351.080403166636
3.70
8.6797e-06
2.376e-08
d
yr
n .2664534243530134 1.7118e-09 deg/d
Q 3.228347501648012 1.3826e-08 au
  Orbit Determination Parameters
   # obs. used (total)      670  
   data-arc span      9511 days (26.04 yr)  
   first obs. used      1995-03-01  
   last obs. used      2021-03-15  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .57888  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Apr-13 02:30:28  

Additional Information
 Earth MOID = .542265 au 
 Jupiter MOID = 2.14018 au 
 T_jup = 3.442 
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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 15.85   n/a E2021B10  

18499 Showalter           Discovered 1996 June 22 by NEAT at Haleakala.
Mark R. Showalter (b. 1957), planetary scientist at the SETI Institute, is (co-)discover of the Jovian gossamer ring, Saturnian moon Pan, Uranian moons Mab and Cupid, two faint Uranian rings, Neptunian moon S/2004 N 1, and Plutonian moons Kerberos and Styx. He is the leader of the Planetary Data Systems Rings Node.
NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character)
Reference: MPC batch dated 2014-09-09Last Updated: 2014-11-10

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Alternate Designations
 1996 MR = 1995 FW6 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
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