+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   21343 (1997 EF) Classification: Main-belt Asteroid          SPK-ID: 2021343 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] [ show orbit diagram ] Orbital Elements at Epoch 2459396.5 (2021-Jul-01.0) TDB Reference: JPL 37 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1388938519587828 3.2779e-08   a 2.443324112143939 7.0804e-09 au q 2.103961414624494 8.0344e-08 au i 3.903644890377603 2.7701e-06 deg node 72.37920183107326 5.387e-05 deg peri 129.1550339939288 5.5006e-05 deg M 106.4060623203252 1.0736e-05 deg tp 2458984.180457481030 (2020-May-14.68045748) 4.1784e-05 TDB period 1394.986639576792 3.82 6.0637e-06 1.66e-08 d yr n .2580669877305892 1.1218e-09 deg/d Q 2.782686809663384 8.0638e-09 au   Orbit Determination Parameters    # obs. used (total)      2142      data-arc span      10850 days (29.71 yr)      first obs. used      1991-10-08      last obs. used      2021-06-22      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .49129      source      ORB      producer      Otto Matic      solution date      2021-Jul-08 18:32:41   Additional Information  Earth MOID = 1.10395 au   Jupiter MOID = 2.17494 au   T_jup = 3.484  [ show covariance matrix ] [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes absolute magnitude H 14.46   n/a E2021B10   diameter diameter 3.505 km 0.660 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   geometric albedo albedo 0.329   0.217 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   21343 (1997 EF)          Discovered 1997-Mar-01 by Kobayashi, T. at Oizumi Reference: 20010208/Numbers.arc Last Updated: 2004-04-19 Alternate Designations  1997 EF = 1999 VK68  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-Jul-31 05:56 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin