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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 ]

[ show orbit diagram ]
Orbital Elements at Epoch 2459396.5 (2021-Jul-01.0) TDB
Reference: JPL 18 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .3498875416974074 3.7721e-08  
a 2.391385097730548 1.0196e-08 au
q 1.554669244633792 9.0921e-08 au
i 4.285710498453486 4.2713e-06 deg
node 134.6113323290555 5.4925e-05 deg
peri 193.394034907472 5.5503e-05 deg
M 264.315840787624 1.3446e-05 deg
tp 2459755.513061268367
(2022-Jun-25.01306127)
5.2462e-05 TDB
period 1350.742935094896
3.70
8.6385e-06
2.365e-08
d
yr
n .2665199947721424 1.7045e-09 deg/d
Q 3.228100950827304 1.3763e-08 au
  Orbit Determination Parameters
   # obs. used (total)      706  
   data-arc span      9560 days (26.17 yr)  
   first obs. used      1995-03-01  
   last obs. used      2021-05-03  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .56828  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Jul-08 18:00:57  

Additional Information
 Earth MOID = .542928 au 
 Jupiter MOID = 2.14032 au 
 T_jup = 3.442 
[ 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 15.86   n/a MPCxxxxx  

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

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