+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   18347 (1989 WU) Classification: Main-belt Asteroid          SPK-ID: 2018347 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] [ show orbit diagram ] Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB Reference: JPL 30 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1554600374861664 3.3035e-08   a 2.231885984795742 6.1056e-09 au q 1.884916905934547 7.3541e-08 au i 4.959816843931563 3.6979e-06 deg node 270.1802140173432 4.4209e-05 deg peri 174.9461679260627 4.6695e-05 deg M 42.33382917397782 1.2933e-05 deg tp 2458857.284017521723 (2020-Jan-08.78401752) 4.3858e-05 TDB period 1217.885428702766 3.33 4.9975e-06 1.368e-08 d yr n .2955943075724742 1.213e-09 deg/d Q 2.578855063656937 7.0548e-09 au   Orbit Determination Parameters    # obs. used (total)      1835      data-arc span      11111 days (30.42 yr)      first obs. used      1989-11-20      last obs. used      2020-04-22      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .44925      source      ORB      producer      Otto Matic      solution date      2020-May-20 04:47:59   Additional Information  Earth MOID = .90119 au   Jupiter MOID = 2.62511 au   T_jup = 3.620  [ 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 14.2   n/a MPO412322   diameter diameter 3.988 km 0.069 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   geometric albedo albedo 0.255   0.043 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   18347 (1989 WU)          Discovered 1989-Nov-20 by Oohira at Oohira Reference: 20001111/Numbers.arc Last Updated: 2004-04-19 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2020-Aug-06 17:39 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin