+ View the NASA Portal + Near-Earth Object (NEO) Program Search JPL JPL Small-Body Database Browser Search: [ help ]   103P/Hartley 2 Classification: Jupiter-family Comet [NEO]          SPK-ID: 1000041 [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ] [ show orbit diagram ] alternate orbits: [epoch=2010-09-17.0] 183 (default) [epoch=2007-11-12.0] 161 [epoch=1997-12-18.0] SAO/1997 [epoch=1991-09-21.0] SAO/1991 [epoch=1985-06-24.0] SAO/1985 Orbital Elements at Epoch 2455456.5 (2010-Sep-17.0) TDB Reference: JPL 183 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .6951452964967095 1.3729e-06   a 3.472769398388862 1.4784e-05 AU q 1.058690085281137 3.5518e-07 AU i 13.61716956119923 2.3585e-05 deg node 219.7626609177958 5.3186e-05 deg peri 181.1954811299036 0.00011319 deg M 353.7167049330382 3.6019e-05 deg tp 2455497.756967202996 (2010-Oct-28.25696720) 3.8839e-05 JED period 2363.808803309979 6.47 0.015094 4.133e-05 d yr n .1522965814730453 9.7251e-07 deg/d Q 5.886848711496587 2.5061e-05 AU Additional Model Parameters  Parameter Value Uncertainty (1-sigma)  A1 [EST] 7.225261187420759E-10 8.666E-10 A2 [EST] -1.525011674392043E-9 3.204E-10 A3 [EST] -3.798639416296654E-10 4.441E-10   Orbit Determination Parameters    # obs. used (total)      2638      # delay obs. used      1      # Doppler obs. used      1      data-arc span      84 days      first obs. used      2010-08-01      last obs. used      2010-10-24      planetary ephem.      DE405      SB-pert. ephem.      SB405-CPV-2      condition code      2      fit RMS      .37548      data source      ORB      producer      Steven R. Chesley      solution date      2010-Oct-24 11:48:36   Additional Information  Earth MOID = .0668221 AU   T_jup = 2.640  [ 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 14.6 mag 1. 183 from 277 observations, assumed slope, autocmod 2.4a comet total magnitude slope K1 17.   n/a 183 autocmod 2.4a comet nuclear magnitude M2 17.7 mag 0.7 183 from 1984 observations, autocmod 2.4a comet nuclear magnitude slope K2 5.   n/a 183 autocmod 2.4a comet nuclear phase coefficient PC 0.03   n/a 183 autocmod 2.4a diameter diameter 1.6 km n/a Lamy,P.L.,Toth,I.,Fernandez,Y.R.,Weaver,H.A. (2004) Comets II, pp. 223-264   rotation period rot_per 18.1 h n/a Asteroid Lightcurve DataBase (Rev. 2013-May-01) Result based on less than full coverage, so that the period may be wrong by 30 percent or so. Published Reference List: [Harmon, J.K.; Nolan, M.C; Howell, E.S.; Giorgini, J.D. (2010) CBET 2515.] [Belton, M.J.S.; Thomas, P.; Lie, J.-Y.; Williams, J.; et al. (2012) Icarus, in press.] 103P/Hartley 2          Discovered 1986-Mar-15 by Hartley, Malcolm at U. K. Schmidt Telescope Unit, Siding Spring Reference: comet.dis Last Updated: 2003-08-29 [ show close-approach data ] Alternate Designations  Perihelion  Year (est.)  New-Style  Desig Roman  Numeral  Year/  Letter   1991.4   103P/1991 N1   1991 XV   1991t   1984.9   103P/1986 E2   1985 V   1986c  [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2013-May-18 06:01 UT (server date/time)   Site Manager:   Donald K. Yeomans Webmaster:   Alan B. Chamberlin