+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   152655 (1997 WL18) Classification: Main-belt Asteroid          SPK-ID: 2152655 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] [ show orbit diagram ] Orbital Elements at Epoch 2459200.5 (2020-Dec-17.0) TDB Reference: JPL 13 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1241481830072647 4.8056e-08   a 2.428560102706789 1.7758e-08 au q 2.127058778631805 1.1585e-07 au i 4.138527700562415 5.8223e-06 deg node 275.0966443056959 8.912e-05 deg peri 62.6635586937988 9.3727e-05 deg M 92.05014345108445 3.15e-05 deg tp 2458847.037227445807 (2019-Dec-29.53722745) 0.00011913 TDB period 1382.361757938253 3.78 1.5162e-05 4.151e-08 d yr n .260423870909832 2.8565e-09 deg/d Q 2.730061426781773 1.9963e-08 au   Orbit Determination Parameters    # obs. used (total)      316      data-arc span      8497 days (23.26 yr)      first obs. used      1997-11-06      last obs. used      2021-02-10      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .53216      source      ORB      producer      Otto Matic      solution date      2021-Apr-13 19:28:04   Additional Information  Earth MOID = 1.11953 au   Jupiter MOID = 2.61396 au   T_jup = 3.495  [ 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 16.4   n/a MPO436771   diameter diameter 2.985 km 0.834 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   geometric albedo albedo 0.055   0.026 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   152655 (1997 WL18)          Discovered 1997-Nov-23 by Spacewatch at Kitt Peak Reference: 20070402/Numbers.arc Last Updated: 2007-04-04 [ show close-approach data ] Alternate Designations  1997 WL18 = 2001 XJ229  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Apr-17 22:03 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin