+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   (1998 US18) Classification: Apollo [NEO, PHA]          SPK-ID: 3014683 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Close-Approach Data ] [ show orbit diagram ] Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB Reference: JPL 15 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .6766397551613287 1.6062e-06   a 2.606180089770204 1.2998e-07 au q .8427350319217636 4.228e-06 au i 9.65285562793923 6.23e-05 deg node 207.3374817448967 2.9873e-05 deg peri 115.3601346318531 0.00054591 deg M 59.89566597986519 5.4121e-05 deg tp 2458744.819293181571 (2019-Sep-18.31929318) 0.00021192 TDB period 1536.756507316851 4.21 0.00011496 3.147e-07 d yr n .2342596229695187 1.7525e-08 deg/d Q 4.369625147618645 2.1792e-07 au   Orbit Determination Parameters    # obs. used (total)      68      data-arc span      7704 days (21.09 yr)      first obs. used      1998-10-25      last obs. used      2019-11-28      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .48682      source      ORB      producer      Otto Matic      solution date      2019-Nov-28 08:09:34   Additional Information  Earth MOID = .0336967 au   Jupiter MOID = 1.28235 au   T_jup = 3.024  [ show covariance matrix ] [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Close-Approach Data ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes absolute magnitude H 20.9   n/a E2019-WG3   [ show close-approach data ] Alternate Designations  1998 US18 = 2019 VC1  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Close-Approach Data ] 2021-Jan-18 18:01 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin