+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   103210 (1999 XK257) Classification: Main-belt Asteroid          SPK-ID: 2103210 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] [ show orbit diagram ] Orbital Elements at Epoch 2459200.5 (2020-Dec-17.0) TDB Reference: JPL 16 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .06436278322339563 3.6789e-08   a 2.618674139227151 1.164e-08 au q 2.450128983271362 9.683e-08 au i 4.098070440299782 4.027e-06 deg node 279.3853979118075 5.2714e-05 deg peri 129.4834797471811 6.1321e-05 deg M 14.80878460774639 2.9856e-05 deg tp 2459136.829606852009 (2020-Oct-14.32960685) 0.00012841 TDB period 1547.820576800519 4.24 1.032e-05 2.825e-08 d yr n .2325850976501111 1.5508e-09 deg/d Q 2.787219295182941 1.2389e-08 au   Orbit Determination Parameters    # obs. used (total)      850      data-arc span      7711 days (21.11 yr)      first obs. used      1999-12-07      last obs. used      2021-01-16      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .50483      source      ORB      producer      Otto Matic      solution date      2021-Feb-24 08:33:42   Additional Information  Earth MOID = 1.46197 au   Jupiter MOID = 2.44964 au   T_jup = 3.399  [ 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 15.3   n/a MPO264069   103210 (1999 XK257)          Discovered 1999-Dec-07 by LINEAR at Socorro Reference: 20051019/Numbers.arc Last Updated: 2005-10-26 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-Mar-02 08:05 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin