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1981 Midas (1973 EA)
Classification: Apollo [NEO, PHA]          SPK-ID: 2001981
[ 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 224 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .6503351033312937 2.2639e-08  
a 1.776336299557504 2.7183e-09 au
q .6211224486336467 4.0542e-08 au
i 39.83111804507288 6.1046e-06 deg
node 356.8629785154508 1.8004e-06 deg
peri 267.8249087248357 5.124e-06 deg
M 35.99115839863182 1.6734e-06 deg
tp 2459114.047105737895
(2020-Sep-21.54710574)		 3.8948e-06 TDB
period 864.7413231228727
2.37		 1.985e-06
5.435e-09		 d
yr
n .4163094677838669 9.5562e-10 deg/d
Q 2.931550150481362 4.4862e-09 au
   Orbit Determination Parameters
   # obs. used (total)      1068  
   # delay obs. used      6  
   # Doppler obs. used      1  
   data-arc span      17508 days (47.93 yr)  
   first obs. used      1973-03-06  
   last obs. used      2021-02-10  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .39079  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Feb-24 19:04:57  

Additional Information
 Earth MOID = .00328786 au 
 Jupiter MOID = 3.31333 au 
 T_jup = 3.611 
[ 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 15.22   n/a E2021B10  
diameter diameter 3.4 km n/a Hazards due to Comets and Asteroids (1994), Ed. T. Gehrels, pp.540-543 based on assumed medium albedo (0.15)
rotation period rot_per 5.220 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List:
[Mottola, S.; De Angelis, G.; Di Martino, M.; Erikson, A.; et al. (1995) Icarus 117, 62-70; Mottola, S.; De Angelis, G.; Di Martino, M.; Erikson, A.; Harris, A.W.; Hahn, G.; Neukum, G.; Pravec, M.; Wolf, M. (1995) Lunar & Planetary Science XXVI, 1003-1004.]
[Wisniewski, W.Z.; Michalowski, T.M.; Harris, A.W.; McMillan, R.S. (1997) Icarus 126, 395-449; 1995, Lunar & Planetary Sci. XXVI, 1511-1512.]
[Torppa, J.; Aksnes, K.; Dai, Z.; Grav, T.; et al. (2005) Bull. Amer. Astron. Soc. 37, 643.]
[Franco, L.; Marchini, A.; Baj, G.; Scarfi, G.; et al. (2018) Minor Planet Bull. 45, 273-275.]
SMASSII spectral type spec_B V   n/a Binzel et al. (2001) Icarus 151, 139-149  

1981 Midas (1973 EA)          Discovered 1973-Mar-06 by Kowal, C. at Palomar
Reference: DISCOVERY.DBLast Updated: 2003-08-29

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