+ 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-14.0] 66 (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 2455210.5 (2010-Jan-14.0) TDB Reference: JPL 66 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .367807917750657 9.4262e-08   a 3.64209653546085 3.5533e-08 au q 2.302504592506113 3.376e-07 au i 13.66072398811014 9.53e-06 deg node 117.2894093488922 2.043e-05 deg peri 207.8209315334678 2.717e-05 deg M 271.6645296016229 9.9384e-06 deg tp 2455833.457231084971 (2011-Sep-28.95723108) 7.1832e-05 TDB period 2538.783143160912 6.95 3.7153e-05 1.017e-07 d yr n .1418002167573013 2.0751e-09 deg/d Q 4.981688478415587 4.8602e-08 au Additional Model Parameters  Parameter Value Uncertainty (1-sigma)  A1 [EST] 5.750573803808527E-9 8.842E-11 A2 [EST] -1.751196058818756E-10 2.644E-12   Orbit Determination Parameters    # obs. used (total)      2123      data-arc span      25665 days (70.27 yr)      first obs. used      1949-09-24      last obs. used      2019-12-31      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .73831      source      ORB      producer      Davide Farnocchia      solution date      2020-Jan-13 10:42:44   Additional Information  Earth MOID = 1.29756 au   Jupiter MOID = .47453 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 66 2 parameter fit from 840 observations, autocmod 2.8 comet total magnitude slope K1 15.75   n/a 66 autocmod 2.8 comet nuclear magnitude M2 13.5   0.7 66 from 985 observations, autocmod 2.8 comet nuclear magnitude slope K2 5.   n/a 66 autocmod 2.8 comet nuclear phase coefficient PC 0.03   n/a 66 autocmod 2.8 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-Jan-17 20:07 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin