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1656 Suomi (1942 EC)
Classification: Mars-crossing Asteroid          SPK-ID: 2001656
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]

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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.

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Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB
Reference: JPL 29 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1231716011440729 3.7288e-08  
a 1.877881929480352 4.3689e-09 au
q 1.646580205466736 6.9925e-08 au
i 25.06585141748207 4.6515e-06 deg
node 175.5387841626828 9.8359e-06 deg
peri 287.4991618591078 2.0753e-05 deg
M 197.7486039640332 1.975e-05 deg
tp 2459424.130082736565
5.1869e-05 TDB
period 939.9415568132099
n .3830025360518676 1.3366e-09 deg/d
Q 2.109183653493968 4.907e-09 au
  Orbit Determination Parameters
   # obs. used (total)      2037  
   data-arc span      28187 days (77.17 yr)  
   first obs. used      1942-03-10  
   last obs. used      2019-05-12  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .37496  
   source      ORB  
   producer      Otto Matic  
   solution date      2019-May-29 19:25:53  

Additional Information
 Earth MOID = .754228 au 
 Jupiter MOID = 3.03066 au 
 T_jup = 3.851 
[ 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 12.8   n/a MPO425817  
diameter diameter 7.86 km 0.7 IRAS-A-FPA-3-RDR-IMPS-V6.0 IRAS observations used: 3
rotation period rot_per 2.583 h n/a LCDB (Rev. 2019-August); Warner et al., 2009 Published Reference List:
[Stephens, R.D. (2004) Minor Planet Bull. 31, 95-97.]
[Brinsfield, J.W. (2008) Minor Planet Bull. 35, 23-24.]
[Warner, B.D. (2009) Minor Planet Bull. 36, 109-116.]
[Warner, B.D. (2012) Minor Planet Bull. 39, 245-252.]
[Warner, B.D. (2014) Minor Planet Bull. 41, 144-155.]
[Warner, B.D. (2016) Minor Planet Bull. 43, 57-65.]
[Warner, B.D. (2017) Minor Planet Bull. 44, 289-294.]
geometric albedo albedo 0.1556   0.032 IRAS-A-FPA-3-RDR-IMPS-V6.0 IRAS observations used: 3
Tholen spectral type spec_T S   n/a EAR-A-5-DDR-TAXONOMY-V4.0 based on a medium resolution spectrum published by Chapman and Gaffey (1979)

1656 Suomi (1942 EC)          Discovered 1942-Mar-11 by Vaisala, Y. at Turku
Reference: DISCOVERY.DBLast Updated: 2003-08-29

Alternate Designations
 1942 EC = 1955 HL 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
FirstGov 2020-Feb-19 02:07 UT
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