+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   2540 Blok (1971 TH2) Classification: Main-belt Asteroid          SPK-ID: 2002540 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] [ show orbit diagram ] Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB Reference: JPL 28 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .05121909832323697 4.1824e-08   a 2.196206207176413 5.9425e-09 au q 2.083718505512941 9.1478e-08 au i 1.265945947262655 3.5351e-06 deg node 183.4711886042058 0.00019272 deg peri 262.2302242331849 0.00019595 deg M 267.5774732555552 3.6617e-05 deg tp 2459305.699231447753 (2021-Apr-01.19923145) 0.00012132 TDB period 1188.79809058883 3.25 4.825e-06 1.321e-08 d yr n .3028268659328739 1.2291e-09 deg/d Q 2.308693908839885 6.2469e-09 au   Orbit Determination Parameters    # obs. used (total)      2265      data-arc span      25717 days (70.41 yr)      first obs. used      1950-03-08      last obs. used      2020-08-04      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .43398      source      ORB      producer      Otto Matic      solution date      2020-Aug-24 22:52:51   Additional Information  Earth MOID = 1.10032 au   Jupiter MOID = 2.76995 au   T_jup = 3.667  [ 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 13.1   n/a MPO389604   diameter diameter 5.671 km 0.122 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   rotation period rot_per 19.20 h n/a LCDB (Rev. 2019-August); Warner et al., 2009 [Result based on fragmentary lightcurve(s), may be completely wrong.] geometric albedo albedo 0.302   0.033 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2012ApJ...759L...8M)   2540 Blok (1971 TH2)          Discovered 1971-Oct-13 by Chernykh, L. at Nauchnyj Reference: DISCOVERY.DB Last Updated: 2003-08-29 Alternate Designations  1971 TH2 = 1950 ED = 1957 JQ = 1960 FK = 1968 UZ = 1980 LN = 1981 UQ  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2020-Oct-21 19:29 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin