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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 ]

[ show orbit diagram ]
Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB
Reference: JPL 14 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .3496293733697202 3.9223e-08  
a 2.39203513854401 1.0315e-08 au
q 1.555709391976516 9.4272e-08 au
i 4.285264426009027 4.7188e-06 deg
node 134.6089337669301 6.1778e-05 deg
peri 193.354993049984 6.2326e-05 deg
M 158.8589914565394 1.2876e-05 deg
tp 2458404.207894347645
(2018-Oct-12.70789435)
4.5139e-05 TDB
period 1351.293723236156
3.70
8.7408e-06
2.393e-08
d
yr
n .2664113610606073 1.7233e-09 deg/d
Q 3.228360885111504 1.3922e-08 au
  Orbit Determination Parameters
   # obs. used (total)      636  
   data-arc span      9104 days (24.93 yr)  
   first obs. used      1995-03-01  
   last obs. used      2020-02-02  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .58138  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Feb-22 22:27:12  

Additional Information
 Earth MOID = .54469 au 
 Jupiter MOID = 2.13981 au 
 T_jup = 3.442 
[ 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 15.8   n/a MPO452433  

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

[ hide close-approach data ]
Close-Approach Data   ...sorted by Date/Time (TDB)
Date/Time (TDB) Time Uncertainty
(days_HH:MM)
Body Nominal Distance (au) Minimum Distance (au) Maximum Distance (au) V-relative (km/s) V-infinity (km/s) JD (TDB) Time Uncertainty (minutes) Semi-major axis (km) Semi-minor axis (km) range-LOV angle (deg) N-sigma BP Orbit Ref. Reference Modified
2076-Oct-21 06:17 < 00:01 Juno 0.00537407054166538 0.00537154581454921 0.00537659923087597 8.58019346591382 8.58019320207085 2479597.761780929 0.343059805266891 281.844778273977 51.5469927758397 -65.4926097564632 14235.2925472228 T 14 CATAB v2.0f-lin.ifort 2020-Feb-22 22:27:25 2020-Feb-22 22:27
2190-Jan-21 18:37 00:01 Europ 0.0445418643142657 0.044529090162181 0.0445546402476376 6.43074318884749 6.43074315174166 2520962.275570395 1.02552890932498 777.502801281304 58.2668871069142 -35.1130122686289 66131.6712151446 T 14 CATAB v2.0f-lin.ifort 2020-Feb-22 22:27:25 2020-Feb-22 22:27

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