+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   120988 (1998 XM18) Classification: Main-belt Asteroid          SPK-ID: 2120988 [ 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 17 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1427409986735141 4.0114e-08   a 3.169841453675221 2.7077e-08 au q 2.717375118940916 1.3566e-07 au i .6647392684475903 4.7513e-06 deg node 119.4876131448542 0.00044474 deg peri 339.7886340277716 0.00044521 deg M 254.5904949042225 2.0179e-05 deg tp 2459604.076067704103 (2022-Jan-24.57606770) 0.00011827 TDB period 2061.364240122793 5.64 2.6412e-05 7.231e-08 d yr n .1746416247031409 2.2377e-09 deg/d Q 3.622307788409526 3.0942e-08 au   Orbit Determination Parameters    # obs. used (total)      538      data-arc span      7958 days (21.79 yr)      first obs. used      1998-12-08      last obs. used      2020-09-21      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .57195      source      ORB      producer      Otto Matic      solution date      2020-Oct-22 20:16:10   Additional Information  Earth MOID = 1.73426 au   Jupiter MOID = 1.53646 au   T_jup = 3.186  [ 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 15.5   n/a MPO449702   diameter diameter 3.476 km 0.500 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   geometric albedo albedo 0.092   0.047 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   120988 (1998 XM18)          Discovered 1998-Dec-08 by Spacewatch at Kitt Peak Reference: 20060314/Numbers.arc Last Updated: 2006-03-23 [ show close-approach data ] Alternate Designations  1998 XM18 = 2000 EB138  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2020-Oct-25 23:24 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin