+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   12620 Simaqian (6335 P-L) Classification: Main-belt Asteroid          SPK-ID: 2012620 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] [ show orbit diagram ] Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB Reference: JPL 22 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .144631148686279 2.9167e-08   a 3.095552423223995 1.834e-08 au q 2.647839120434514 9.0703e-08 au i .9185413786388961 4.5575e-06 deg node 180.018889289489 0.00024797 deg peri 59.27905190908309 0.00024861 deg M 79.94497133783665 1.8054e-05 deg tp 2458558.731930815708 (2019-Mar-16.23193082) 9.8917e-05 TDB period 1989.324684779461 5.45 1.7679e-05 4.84e-08 d yr n .18096593419586 1.6083e-09 deg/d Q 3.543265726013476 2.0993e-08 au   Orbit Determination Parameters    # obs. used (total)      1438      data-arc span      21057 days (57.65 yr)      first obs. used      1960-09-24      last obs. used      2018-05-20      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .54597      source      ORB      producer      Otto Matic      solution date      2018-May-31 13:23:11   Additional Information  Earth MOID = 1.63574 au   Jupiter MOID = 1.46487 au   T_jup = 3.207  [ 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 13.8   n/a MPO473937   12620 Simaqian           Discovered 1960 Sept. 24 by C. J. van Houten and I. van Houten-Groeneveld on Palomar Schmidt plates taken by T. Gehrels. Sima Qian (c. 145 B.C.-c. 85 B.C.) was a Chinese historian, counselor and court astrologer of the Han emperor Wu Di. He wrote a treatise on the Chinese calendar. His Shiji ("Records of the Grand Historian") contains the earliest systematical description of the Chinese constellations. NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character) Reference: 20080122/MPCPages.arc Last Updated: 2008-03-05 [ show close-approach data ] Alternate Designations  6335 P-L = 1992 OD8 = 1996 DD7  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2020-Jul-14 01:48 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin