+ View the NASA Portal + Near-Earth Object (NEO) Program Search JPL JPL Small-Body Database Browser Search: [ help ]   22320 (1991 PH18) Classification: Main-belt Asteroid          SPK-ID: 2022320 [ 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 .2145747745238819 8.5916e-08   a 2.440527093129175 2.1883e-08 AU q 1.916851542401558 2.0846e-07 AU i 12.34945005719041 1.027e-05 deg node 156.0514804215076 3.301e-05 deg peri 149.8946755086447 3.9142e-05 deg M 264.9161015863441 1.9586e-05 deg tp 2456768.314084472751 (2014-Apr-20.81408447) 7.7414e-05 JED period 1392.591938480863 3.81 1.873e-05 5.128e-08 d yr n .2585107597224162 3.4769e-09 deg/d Q 2.964202643856793 2.6578e-08 AU   Orbit Determination Parameters    # obs. used (total)      564      data-arc span      7917 days (21.68 yr)      first obs. used      1991-08-08      last obs. used      2013-04-11      planetary ephem.      DE405      SB-pert. ephem.      SB405-CPV-2      condition code      0      fit RMS      .58356      data source      ORB      producer      Otto Matic      solution date      2013-Apr-29 14:32:18   Additional Information  Earth MOID = .912677 AU   T_jup = 3.439  [ 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 14.6 mag n/a PDS3 (MPO 9961)   22320 (1991 PH18)          Discovered 1991-Aug-08 by Holt, H. E. at Palomar (675) Reference: 20010309/Numbers.arc Last Updated: 2004-04-19 Alternate Designations  1991 PH18 = 1998 HU112  [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ] 2013-May-25 00:16 UT (server date/time)   Site Manager:   Donald K. Yeomans Webmaster:   Alan B. Chamberlin