+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   C/2021 A1 (Leonard) Classification: Hyperbolic Comet          SPK-ID: 1003751 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Close-Approach Data ] [ show orbit diagram ] Orbital Elements at Epoch 2459255.5 (2021-Feb-10.0) TDB Reference: JPL 6 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e 1.000097091543852 5.904e-06   a -6334.697030737982 385.19 au q .6150455145494623 7.8224e-06 au i 132.6862156505232 2.021e-05 deg node 255.8782136373354 0.0003611 deg peri 225.0877384372308 0.00053798 deg M -.0006397858450716127 5.8351e-05 deg tp 2459582.779894519014 (2022-Jan-03.27989452) 0.0023126 TDB period n/a n/a n/a n/a d yr n 1.95485838203374E-6 1.783e-07 deg/d Q n/a n/a au   Orbit Determination Parameters    # obs. used (total)      613      data-arc span      385 days (1.05 yr)      first obs. used      2020-04-11      last obs. used      2021-05-01      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      norm. resid. RMS      .50469      source      ORB      producer      Otto Matic      solution date      2021-May-02 23:42:50   Additional Information  Earth MOID = .231005 au   Jupiter MOID = .296419 au  [ 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 comet total magnitude M1 10.0   0.5 6 2 parameter fit from 540 observations, autocmod 2.9c comet total magnitude slope K1 8.25   n/a 6 autocmod 2.9c comet nuclear magnitude M2 12.5   0.3 6 from 21 observations, autocmod 2.9c comet nuclear magnitude slope K2 5.   n/a 6 autocmod 2.9c comet nuclear phase coefficient PC 0.03   n/a 6 autocmod 2.9c [ 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 2021-Dec-12 13:50 00:06 Earth 0.233385237694925 0.233360012630372 0.233410470959329 70.6719010594401 70.6717395147465 2459561.076070180 6.01495200575188 3055.88308232333 782.056034133547 -70.5131554710067 42193.1849764244 T 6 CATAB v2.0g-lin.ifort 2021-May-02 23:42:52 2021-May-02 23:42 2021-Dec-18 02:05 00:05 Venus 0.0285520800827984 0.0284829370299031 0.0286212275693455 78.2341148460164 78.233142686084 2459566.586816770 5.45910140680253 3496.05326583857 821.291857265432 9.78767496998869 1488.82951653808 T 6 CATAB v2.0g-lin.ifort 2021-May-02 23:42:52 2021-May-02 23:42 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Close-Approach Data ] 2021-May-11 19:24 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin