+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   4923 Clarke (1981 EO27) Classification: Main-belt Asteroid          SPK-ID: 2004923 [ 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 32 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .2016289156571559 3.2158e-08   a 2.144806299960712 6.3518e-09 au q 1.712351331404997 7.1176e-08 au i 6.675054556398381 3.2039e-06 deg node 188.4884564739562 2.872e-05 deg peri 108.5616296681276 3.0348e-05 deg M 78.70059482818687 7.4436e-06 deg tp 2458749.683527346476 (2019-Sep-23.18352735) 2.3728e-05 TDB period 1147.309373612634 3.14 5.0966e-06 1.395e-08 d yr n .3137776159419289 1.3939e-09 deg/d Q 2.577261268516426 7.6325e-09 au   Orbit Determination Parameters    # obs. used (total)      2086      data-arc span      17656 days (48.34 yr)      first obs. used      1972-07-13      last obs. used      2020-11-14      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .48662      source      ORB      producer      Otto Matic      solution date      2020-Dec-18 02:19:53   Additional Information  Earth MOID = .711501 au   Jupiter MOID = 2.65597 au   T_jup = 3.675  [ 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 14.3   n/a MPO267727   diameter diameter 3.367 km 0.033 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   rotation period rot_per 3.143 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: [Pravec, P.; Wolf, M.; Sarounova, L. (2013) http://www.asu.cas.cz/~ppravec/neo.htm] [Aznar, A.M. (2017) Minor Planet Bull. 44, 60-63.] geometric albedo albedo 0.366   0.066 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   SMASSII spectral type spec_B S   n/a EAR-A-5-DDR-TAXONOMY-V4.0 based on a high-resolution spectrum by Xu et al. (1995) or Bus and Binzel (2002) 4923 Clarke (1981 EO27)          Discovered 1981-Mar-02 by Bus, S. J. at Siding Spring Reference: DISCOVERY.DB Last Updated: 2003-08-29 [ show close-approach data ] Alternate Designations  1981 EO27 = 1972 NJ  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Jan-25 08:44 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin