+ View the NASA Portal + Near-Earth Object (NEO) Program Search JPL JPL Small-Body Database Browser Search: [ help ]   7521 (1990 QS2) Classification: Main-belt Asteroid          SPK-ID: 2007521 [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ] [ show orbit diagram ] Orbital Elements at Epoch 2456400.5 (2013-Apr-18.0) TDB Reference: JPL 1 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .008600704720047756 7.2164e-08   a 2.900841478643255 2.8948e-08 AU q 2.875892197645777 2.1006e-07 AU i 2.649025976351785 6.5855e-06 deg node 143.2786046974766 0.00016175 deg peri 9.794379426739029 0.00047084 deg M 48.30947321912831 0.00043957 deg tp 2456158.333411915297 (2012-Aug-18.83341192) 0.0022043 JED period 1804.614414134696 4.94 2.7013e-05 7.396e-08 d yr n .1994885983289778 2.9861e-09 deg/d Q 2.925790759640732 2.9197e-08 AU   Orbit Determination Parameters    # obs. used (total)      1109      data-arc span      10964 days (30.02 yr)      first obs. used      1983-04-16      last obs. used      2013-04-22      planetary ephem.      DE405      SB-pert. ephem.      SB405-CPV-2      condition code      0      fit RMS      .5235      data source      ORB      producer      Otto Matic      solution date      2013-Apr-29 13:26:46   Additional Information  Earth MOID = 1.88261 AU   T_jup = 3.285  [ show covariance matrix ] [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes absolute magnitude H 12.5 mag n/a PDS3 (MPC 29291)   7521 (1990 QS2)          Discovered 1990-Aug-24 by Holt, H. E. at Palomar (675) Reference: DISCOVERY.DB Last Updated: 2003-08-29 Alternate Designations  1990 QS2 = 1983 HQ1 = 1985 SB4 = 1986 WC7  [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ] 2013-May-25 05:38 UT (server date/time)   Site Manager:   Donald K. Yeomans Webmaster:   Alan B. Chamberlin