+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   11876 Doncarpenter (1990 EM1) Classification: Main-belt Asteroid          SPK-ID: 2011876 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] [ show orbit diagram ] Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB Reference: JPL 31 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1554860001777244 3.4543e-08   a 2.430724516081678 7.3494e-09 au q 2.052780883542203 8.3852e-08 au i 5.405482653779528 3.5164e-06 deg node 234.1005460905263 3.8754e-05 deg peri 92.50841042240167 4.051e-05 deg M 202.2022159819913 1.3525e-05 deg tp 2459607.236941568398 (2022-Jan-27.73694157) 5.329e-05 TDB period 1384.210179654331 3.79 6.2778e-06 1.719e-08 d yr n .2600761107607951 1.1795e-09 deg/d Q 2.808668148621153 8.4921e-09 au   Orbit Determination Parameters    # obs. used (total)      1960      data-arc span      11019 days (30.17 yr)      first obs. used      1990-02-24      last obs. used      2020-04-26      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .4758      source      ORB      producer      Otto Matic      solution date      2020-May-20 03:37:51   Additional Information  Earth MOID = 1.04992 au   Jupiter MOID = 2.53014 au   T_jup = 3.485  [ 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 absolute magnitude H 14.2   n/a MPO358745   11876 Doncarpenter           Discovered 1990 Mar. 2 by E. W. Elst at the European Southern Observatory. For the past 42 years, Don Carpenter (b. 1938) has been associated with the Stanford research group devoted to passive and active whistler-mode probing of the earth's ionosphere and magnetosphere. In 1966 he discovered the plasmapause in the electron-density distribution of the magnetosphere. NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character) Reference: 20010509/MPCPages.arc Last Updated: 2009-05-11 [ show close-approach data ] Alternate Designations  1990 EM1 = 1995 QR2  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2020-Oct-23 23:03 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin