+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   128P/Shoemaker-Holt 1-B Classification: Jupiter-family Comet          SPK-ID: 1000117 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] [ show orbit diagram ] Orbital Elements at Epoch 2450726.5 (1997-Oct-05.0) TDB Reference: JPL 33 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .3212585112842391 5.3372e-06   a 4.489242443395618 3.4178e-05 au q 3.047035099236322 1.3524e-06 au i 4.361724121462829 2.975e-05 deg node 214.5275829560614 0.00032571 deg peri 210.2169312978122 0.00033926 deg M 355.2035465260782 7.0807e-05 deg tp 2450772.788781930694 (1997-Nov-20.28878193) 0.00052878 TDB period 3474.225609745049 9.51 0.039676 0.0001086 d yr n .1036202136643677 1.1833e-06 deg/d Q 5.931449787554914 4.5158e-05 au   Orbit Determination Parameters    # obs. used (total)      236      data-arc span      942 days (2.58 yr)      first obs. used      1996-09-16      last obs. used      1999-04-16      planetary ephem.      DE431      SB-pert. ephem.      SB431-BIG16      condition code      3      norm. resid. RMS      .54265      source      ORB      producer      Davide Farnocchia      solution date      2016-Nov-21 08:50:16   Additional Information  Earth MOID = 2.06106 au   Jupiter MOID = .148034 au   T_jup = 2.913   Use 128P orbit  [ 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 comet total magnitude M1 5.6   1. 33 from 111 observations, assumed slope, autocmod 2.6g comet total magnitude slope K1 19.   n/a 33 autocmod 2.6g comet nuclear magnitude M2 16.7   0.6 33 from 5 observations, autocmod 2.6g comet nuclear magnitude slope K2 5.   n/a 33 autocmod 2.6g comet nuclear phase coefficient PC 0.03   n/a 33 autocmod 2.6g diameter diameter 4.6 km n/a Lamy,P.L.,Toth,I.,Fernandez,Y.R.,Weaver,H.A. (2004) Comets II, pp. 223-264   [ show close-approach data ] Alternate Designations  Perihelion  Year (est.)  New-Style  Desig Roman  Numeral  Year/  Letter   1988.4   128P-B/1987 U1        [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Apr-19 10:22 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin