+ View the NASA Portal + Near-Earth Object (NEO) Program Search JPL JPL Small-Body Database Browser Search: [ help ]   81P/Wild 2 Classification: Jupiter-family Comet          SPK-ID: 1000107 [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ] [ show orbit diagram ] alternate orbits: [epoch=2013-03-13.0] K103/7 (default) [epoch=1998-09-24.0] J974/1 [epoch=1990-12-15.0] SAO/1990 [epoch=1984-08-08.0] SAO/1984 [epoch=1978-06-21.0] SAO/1978 Orbital Elements at Epoch 2456364.5 (2013-Mar-13.0) TDB Reference: JPL K103/7 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .5373543238379794 5.0809e-08   a 3.450114967981122 4.9074e-08 AU q 1.596180772198334 1.6027e-07 AU i 3.238287173774766 2.7039e-06 deg node 136.1066161686843 8.501e-05 deg peri 41.69284474711376 7.8161e-05 deg M 171.4155019345076 7.5431e-06 deg tp 2455249.958172392958 (2010-Feb-22.45817239) 3.2015e-05 JED period 2340.716291177878 6.41 4.9941e-05 1.367e-07 d yr n .1537990748203164 3.2815e-09 deg/d Q 5.30404916376391 7.5445e-08 AU Additional Model Parameters  Parameter Value Uncertainty (1-sigma)  A1 [EST] 1.704162371955134E-9 2.518E-11 A2 [EST] 4.580785739610615E-10 6.176E-12 A3 [EST] -9.91813916969921E-10 1.43E-11 DT [EST] -135.2388191926564 1.811   Orbit Determination Parameters    # obs. used (total)      4834      data-arc span      6469 days (17.71 yr)      first obs. used      1995-01-02      last obs. used      2012-09-18      planetary ephem.      DE405      SB-pert. ephem.      SB405-CPV-2      condition code      0      fit RMS      .69131      data source      ORB      producer      Ryan S. Park      solution date      2013-Mar-03 19:25:53   Additional Information  Earth MOID = .602456 AU   T_jup = 2.879  [ show covariance matrix ] [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes comet total magnitude M1 8.6 mag 1. K103/7 2 parameter fit from 812 observations, autocmod 2.5b comet total magnitude slope K1 14.   n/a K103/7 autocmod 2.5b comet nuclear magnitude M2 13.1 mag 0.8 K103/7 from 2686 observations, autocmod 2.5b comet nuclear magnitude slope K2 5.   n/a K103/7 autocmod 2.5b comet nuclear phase coefficient PC 0.03   n/a K103/7 autocmod 2.5b diameter diameter 4.0 km n/a Lamy,P.L.,Toth,I.,Fernandez,Y.R.,Weaver,H.A. (2004) Comets II, pp. 223-264   81P/Wild 2          Discovered 1978-Jan-06 by Wild, Paul at Astronomical Institute of Berne, Switzerland discovered on plate/photo taken on discovery date as well as 1/8 Reference: comet.dis Last Updated: 2003-08-29 [ show close-approach data ] Alternate Designations  Perihelion  Year (est.)  New-Style  Desig Roman  Numeral  Year/  Letter   1990.9       1990 XXVIII   1989t   1984.5   81P/1983 S1   1984 XIV   1983s   1978.1   81P/1978 A2   1978 XI   1978b  [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2013-Jun-19 23:48 UT (server date/time)   Site Manager:   Donald K. Yeomans Webmaster:   Alan B. Chamberlin