+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   48P/Johnson Classification: Jupiter-family Comet          SPK-ID: 1000049 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] [ show orbit diagram ] alternate orbits: [epoch=2010-Jan-21.0] 67 (default) [epoch=1997-Nov-08.0] SAO/1997 [epoch=1990-Nov-05.0] SAO/1990 [epoch=1983-Dec-12.0] SAO/1983 [epoch=1977-Jan-17.0] SAO/1977 [epoch=1970-Apr-04.0] SAO/1970 [epoch=1963-Jun-20.0] SAO/1963 [epoch=1956-Jul-26.0] SAO/1956 [epoch=1949-Sep-01.0] SAO/1949 Orbital Elements at Epoch 2455217.5 (2010-Jan-21.0) TDB Reference: JPL 67 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .3678094803102619 9.3249e-08   a 3.642052829805965 3.5251e-08 au q 2.302471271212515 3.3358e-07 au i 13.66070770610938 9.4937e-06 deg node 117.2890536527312 2.0411e-05 deg peri 207.8231274465664 2.7082e-05 deg M 272.654879781851 9.8668e-06 deg tp 2455833.462020300264 (2011-Sep-28.96202030) 7.1242e-05 TDB period 2538.737444682336 6.95 3.6858e-05 1.009e-07 d yr n .1418027692284839 2.0587e-09 deg/d Q 4.981634388399416 4.8216e-08 au Additional Model Parameters  Parameter Value Uncertainty (1-sigma)  A1 [EST] 5.686552049101132E-9 8.646E-11 A2 [EST] -1.735889281740021E-10 2.601E-12   Orbit Determination Parameters    # obs. used (total)      2128      data-arc span      26012 days (71.22 yr)      first obs. used      1949-09-24      last obs. used      2020-12-12      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .74027      source      ORB      producer      Davide Farnocchia      solution date      2021-Jan-19 12:55:38   Additional Information  Earth MOID = 1.2982 au   Jupiter MOID = .474589 au   T_jup = 2.941  [ 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 9.3   0.9 67 2 parameter fit from 844 observations, autocmod 2.9a comet total magnitude slope K1 15.75   n/a 67 autocmod 2.9a comet nuclear magnitude M2 13.5   0.7 67 from 985 observations, autocmod 2.9a comet nuclear magnitude slope K2 5.   n/a 67 autocmod 2.9a comet nuclear phase coefficient PC 0.03   n/a 67 autocmod 2.9a diameter diameter 5.74 km n/a Lamy,P.L.;Toth,I.;Fernandez,Y.R.;Weaver,H.A.; (2004) Comets II, pp. 223-264   48P/Johnson          Discovered 1949-Aug-25 by Johnson, Ernest Leonard at Union Observatory, South Africa discovered on plate/photo taken on discovery date 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 XXIII   1990h   1983.9       1983 XVIII   1983h   1977.0       1977 I   1976h   1970.0       1970 IV   1970h   1963.1       1963 IV   1963c   1956.1   48P/1956 P1   1956 V   1956f   1949.2   48P/1949 Q1   1949 II   1949d  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Mar-07 09:28 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin