+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   101623 (1999 CH18) Classification: Main-belt Asteroid          SPK-ID: 2101623 [ 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 30 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .07781068083562871 4.3168e-08   a 2.38359155542117 9.8257e-09 au q 2.198122673659793 1.0522e-07 au i 13.82579530873245 5.1185e-06 deg node 343.7912154633932 1.4861e-05 deg peri 138.996995668587 3.2752e-05 deg M 288.0193059112638 2.86e-05 deg tp 2459269.256955932396 (2021-Feb-23.75695593) 0.00010701 TDB period 1344.145195604646 3.68 8.3113e-06 2.276e-08 d yr n .2678282087212006 1.6561e-09 deg/d Q 2.569060437182547 1.059e-08 au   Orbit Determination Parameters    # obs. used (total)      1353      data-arc span      7971 days (21.82 yr)      first obs. used      1999-01-19      last obs. used      2020-11-15      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .49804      source      ORB      producer      Otto Matic      solution date      2020-Dec-17 22:29:29   Additional Information  Earth MOID = 1.22676 au   Jupiter MOID = 2.46421 au   T_jup = 3.493  [ 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 14.4   n/a MPO344990   diameter diameter 5.610 km 0.063 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   geometric albedo albedo 0.105   0.007 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   101623 (1999 CH18)          Discovered 1999-Feb-10 by LINEAR at Socorro Reference: 20051019/Numbers.arc Last Updated: 2005-10-26 [ hide close-approach data ] Close-Approach Data   ...sorted by Date/Time (TDB) Date/Time (TDB) Time Uncertainty (days_HH:MM) Body Nominal Distance (au) Minimum Distance (au) Maximum Distance (au) V-relative (km/s) V-infinity (km/s) JD (TDB) Time Uncertainty (minutes) Semi-major axis (km) Semi-minor axis (km) range-LOV angle (deg) N-sigma BP Orbit Ref. Reference Modified 1950-Feb-02 01:30 < 00:01 Thisb 0.0111636876210252 0.0111557170026691 0.0111716590407721 5.76668485224442 5.76668474633347 2433314.562801590 0.48566361557739 424.770322626225 45.0872357783009 -20.8129404755572 13658.6370167632 T 30 CATAB v2.0f-lin.ifort 2020-Dec-17 22:29:32 2020-Dec-17 22:29 Alternate Designations  1999 CH18 = 2001 QX81  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Jan-23 07:53 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin