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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 
[ hide covariance matrix ]
Orbital Elements at Epoch 2457061.5 (2015-Feb-08.0) TDB
Reference: JPL 16 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .3511922019381424 3.8386e-08  
q 1.551032371687175 9.245e-08 au
tp 2457053.472216311324
(2015-Jan-30.97221631)
3.7987e-05 TDB
node 134.6857314118174 5.7144e-05 deg
peri 193.2910168938647 5.7704e-05 deg
i 4.288319409279295 4.5154e-06 deg
  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
 Jupiter MOID = 2.14018 au 
 T_jup = 3.442 
Orbit Covariance (6×6)
  e q tp node peri i
e 1.47346934162251E-15 -3.539776790503937E-15 -1.5904771894875E-13 8.292591659880816E-15 -2.375776952898899E-14 8.03009190117691E-16
q -3.539776790503937E-15 8.547050969150539E-15 5.671726492345621E-13 -2.035523400700576E-14 9.353719566346228E-14 -1.639930076524559E-15
tp -1.5904771894875E-13 5.671726492345621E-13 1.443013102733554E-9 -1.86694438318579E-11 3.239528952447984E-10 2.025064801616416E-12
node 8.292591659880816E-15 -2.035523400700576E-14 -1.86694438318579E-11 3.265477627619683E-9 -3.259724417526484E-9 9.137810637143056E-12
peri -2.375776952898899E-14 9.353719566346228E-14 3.239528952447984E-10 -3.259724417526484E-9 3.32976484863629E-9 -8.695798844381378E-12
i 8.03009190117691E-16 -1.639930076524559E-15 2.025064801616416E-12 9.137810637143056E-12 -8.695798844381378E-12 2.03891611477119E-11

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

[ 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 16 CATAB v2.0f-lin.ifort 2021-Apr-13 02:30:33 2021-Apr-13 02:30
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 16 CATAB v2.0f-lin.ifort 2021-Apr-13 02:30:33 2021-Apr-13 02:30

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