+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   118231 (1996 XQ18) Classification: Main-belt Asteroid          SPK-ID: 2118231 [ 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 22 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .2918889500543998 4.049e-08   a 2.711116788844447 1.5362e-08 au q 1.919771755873785 1.1481e-07 au i 15.52836297491977 6.3395e-06 deg node 9.412867970008637 1.4254e-05 deg peri 45.95688909919355 1.882e-05 deg M 149.3206054449479 1.1127e-05 deg tp 2458524.202148237445 (2019-Feb-09.70214824) 4.7348e-05 TDB period 1630.499862420409 4.46 1.3858e-05 3.794e-08 d yr n .2207911869833555 1.8766e-09 deg/d Q 3.502461821815108 1.9846e-08 au   Orbit Determination Parameters    # obs. used (total)      644      data-arc span      8560 days (23.44 yr)      first obs. used      1996-12-08      last obs. used      2020-05-16      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .52769      source      ORB      producer      Otto Matic      solution date      2021-Apr-13 16:56:18   Additional Information  Earth MOID = .95992 au   Jupiter MOID = 2.08639 au   T_jup = 3.250  [ 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 15.64   n/a E2021B55   diameter diameter 4.743 km 1.332 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2015ApJ...814..117N)   geometric albedo albedo 0.050   0.033 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2015ApJ...814..117N)   118231 (1996 XQ18)          Discovered 1996-Dec-08 by Hergenrother, C. W. at Catalina Station Reference: 20051116/Numbers.arc Last Updated: 2005-11-21 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-Apr-21 22:09 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin