+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   21980 (1999 XA5) Classification: Main-belt Asteroid          SPK-ID: 2021980 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] [ show orbit diagram ] Orbital Elements at Epoch 2459396.5 (2021-Jul-01.0) TDB Reference: JPL 34 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .08499378446531244 4.5359e-08   a 2.952100284429283 1.6407e-08 au q 2.701190109134513 1.3033e-07 au i 2.290405497084702 3.9098e-06 deg node 144.7092215587323 0.00010712 deg peri 195.3791023548571 0.00011016 deg M 164.0216551009405 2.7294e-05 deg tp 2458552.400241595338 (2019-Mar-09.90024160) 0.00013936 TDB period 1852.657277715374 5.07 1.5445e-05 4.229e-08 d yr n .1943154863720603 1.6199e-09 deg/d Q 3.203010459724053 1.7802e-08 au   Orbit Determination Parameters    # obs. used (total)      1245      data-arc span      8742 days (23.93 yr)      first obs. used      1997-04-30      last obs. used      2021-04-06      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .56186      source      ORB      producer      Otto Matic      solution date      2021-Jul-08 18:38:24   Additional Information  Earth MOID = 1.69164 au   Jupiter MOID = 2.11978 au   T_jup = 3.262  [ 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 14.74   n/a MPCxxxxx   diameter diameter 3.623 km 0.650 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   geometric albedo albedo 0.162   0.100 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   21980 (1999 XA5)          Discovered 1999-Dec-04 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-Jul-31 07:21 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin