+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   138971 (2001 CB21) Classification: Apollo [NEO, PHA]          SPK-ID: 2138971 [ 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 175 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .3334579454766005 2.9315e-08   a 1.034366115816757 2.7019e-09 au q .6894485159658902 2.8684e-08 au i 7.898927831124632 3.1325e-06 deg node 353.7266290153026 8.8153e-06 deg peri 271.7987410901699 8.4314e-06 deg M 55.93680209191985 2.0684e-05 deg tp 2458940.795785598880 (2020-Apr-01.29578560) 2.1848e-05 TDB period 384.2464420665875 1.05 1.5055e-06 4.122e-09 d yr n .9368987206851332 3.6709e-09 deg/d Q 1.379283715667625 3.6029e-09 au   Orbit Determination Parameters    # obs. used (total)      1158      # delay obs. used      1      # Doppler obs. used      1      data-arc span      7289 days (19.96 yr)      first obs. used      2001-02-02      last obs. used      2021-01-17      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .40661      source      ORB      producer      Otto Matic      solution date      2021-Jan-18 06:08:00   Additional Information  Earth MOID = .0239178 au   Jupiter MOID = 3.71708 au   T_jup = 5.863  [ 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 18.4   n/a MPO214609   rotation period rot_per 3.3020 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Result based on less than full coverage, so that the period may be wrong by 30 percent or so. Published Reference List: [Galad, A.; Pravec, P.; Kusnirak, P.; Gajdos, S.; et al. (2005) Earth, Moon, and Planets 97, 147-163.] 138971 (2001 CB21)          Discovered 2001-Feb-02 by LINEAR at Socorro Reference: 20061205/Numbers.arc Last Updated: 2006-12-13 [ show close-approach data ] [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Jan-23 05:56 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin