+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   21890 (1999 UG50) Classification: Main-belt Asteroid          SPK-ID: 2021890 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] [ show orbit diagram ] Orbital Elements at Epoch 2459200.5 (2020-Dec-17.0) TDB Reference: JPL 23 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .04791723222081557 3.5599e-08   a 2.965256554611418 1.8195e-08 au q 2.823169667689807 1.1117e-07 au i 10.6922576254643 4.6561e-06 deg node 71.32495942758479 2.9755e-05 deg peri 43.0769404761455 7.213e-05 deg M 338.0745126158865 6.5347e-05 deg tp 2459314.089606248254 (2021-Apr-09.58960625) 0.00033876 TDB period 1865.055838120191 5.11 1.7166e-05 4.7e-08 d yr n .1930237114846104 1.7766e-09 deg/d Q 3.107343441533029 1.9066e-08 au   Orbit Determination Parameters    # obs. used (total)      1163      data-arc span      12740 days (34.88 yr)      first obs. used      1986-03-04      last obs. used      2021-01-19      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .53481      source      ORB      producer      Otto Matic      solution date      2021-Feb-24 02:54:55   Additional Information  Earth MOID = 1.84958 au   Jupiter MOID = 2.03029 au   T_jup = 3.237  [ show covariance matrix ] [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes absolute magnitude H 14.1   n/a MPO358837   21890 (1999 UG50)          Discovered 1999-Oct-30 by CSS at Catalina Reference: 20010208/Numbers.arc Last Updated: 2004-04-19 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-Apr-13 05:50 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin