+ View the NASA Portal + Near-Earth Object (NEO) Program Search JPL JPL Small-Body Database Browser Search: [ help ]   118P/Shoemaker-Levy 4 Classification: Jupiter-family Comet          SPK-ID: 1000150 [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ] [ show orbit diagram ] alternate orbits: [epoch=2012-08-01.0] 49 (default) [epoch=1997-02-01.0] SAO/1997 [epoch=1990-07-08.0] SAO/1990 Orbital Elements at Epoch 2456140.5 (2012-Aug-01.0) TDB Reference: JPL 49 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .4281755715853681 8.2427e-08   a 3.465487939578648 2.5422e-07 AU q 1.981650660227361 3.5693e-07 AU i 8.508415201215824 5.0467e-06 deg node 151.7701853727449 3.7691e-05 deg peri 302.1741670545564 5.244e-05 deg M 143.7890253725979 2.1414e-05 deg tp 2455199.329613667630 (2010-Jan-02.82961367) 8.6327e-05 JED period 2356.378299398522 6.45 0.00025928 7.099e-07 d yr n .1527768270875232 1.6811e-08 deg/d Q 4.949325218929935 3.6307e-07 AU Additional Model Parameters  Parameter Value Uncertainty (1-sigma)  A1 [EST] 4.309324519344644E-9 1.007E-10 A2 [EST] -1.799045336590839E-9 5.244E-12   Orbit Determination Parameters    # obs. used (total)      2065      data-arc span      6237 days (17.08 yr)      first obs. used      1995-06-22      last obs. used      2012-07-19      planetary ephem.      DE405      SB-pert. ephem.      SB405-CPV-2      condition code      0      fit RMS      .88149      data source      ORB      producer      Alan B. Chamberlin      solution date      2012-Aug-02 17:03:34   Additional Information  Earth MOID = 1.01474 AU   T_jup = 2.960  [ 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 10.4 mag 1. 49 2 parameter fit from 548 observations, autocmod 2.5b comet total magnitude slope K1 13.   n/a 49 autocmod 2.5b comet nuclear magnitude M2 13.9 mag 0.8 49 from 1194 observations, autocmod 2.5b comet nuclear magnitude slope K2 5.   n/a 49 autocmod 2.5b comet nuclear phase coefficient PC 0.03   n/a 49 autocmod 2.5b diameter diameter 4.8 km n/a Lamy,P.L.,Toth,I.,Fernandez,Y.R.,Weaver,H.A. (2004) Comets II, pp. 223-264   118P/Shoemaker-Levy 4          Discovered 1991-Feb-09 by Shoemaker, Carolyn & Eugene, & Levy, D. H. at Palomar Mountain Observatory, California (675) discovered on plate/photo taken on discovery date as well as 2/11 Reference: comet.dis Last Updated: 2003-08-29 [ show close-approach data ] Alternate Designations  Perihelion  Year (est.)  New-Style  Desig Roman  Numeral  Year/  Letter   1997.1   118P/1995 M1         1990.7   118P/1991 C2   1990 XII   1991f  [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2013-May-21 10:28 UT (server date/time)   Site Manager:   Donald K. Yeomans Webmaster:   Alan B. Chamberlin