+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   3102 Krok (1981 QA) Classification: Amor [NEO]          SPK-ID: 2003102 [ 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 246 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .4493181918829107 3.0432e-08   a 2.151154456127954 2.188e-09 au q 1.184601625439675 6.4931e-08 au i 8.441614250978535 3.584e-06 deg node 172.063847207065 2.3987e-05 deg peri 154.7422018221563 2.4916e-05 deg M 101.8877451961817 6.2457e-06 deg tp 2458674.344077434860 (2019-Jul-09.84407743) 1.9653e-05 TDB period 1152.406816907854 3.16 1.7582e-06 4.814e-09 d yr n .3123896828083284 4.7661e-10 deg/d Q 3.117707286816232 3.1711e-09 au   Orbit Determination Parameters    # obs. used (total)      1346      data-arc span      14112 days (38.64 yr)      first obs. used      1981-08-21      last obs. used      2020-04-10      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .48971      source      ORB      producer      Otto Matic      solution date      2020-Nov-13 04:03:10   Additional Information  Earth MOID = .184359 au   Jupiter MOID = 2.27867 au   T_jup = 3.555  [ 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 16.2   n/a MPO502183   diameter diameter 1.6 km n/a Hazards due to Comets and Asteroids (1994), Ed. T. Gehrels, pp.540-543 based on assumed medium albedo (0.15) rotation period rot_per 149.4 h n/a LCDB (Rev. 2019-August); Warner et al., 2009 Published Reference List: [Harris, A.W.; Young, J.W.; Dockweiler, T.; Gibson, J.; et al. (1992) Icarus 95, 115-147.] [Pravec, P.; et al. (2005) Icarus 173, 108-131.] B-V BV 0.834   0.021 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=2; phase (min.=24.29, mean=24.39, max.=24.49) deg. U-B UB 0.521   0.056 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=2; phase (min.=24.29, mean=24.39, max.=24.49) deg. Tholen spectral type spec_T QRS   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 7 color indices SMASSII spectral type spec_B S   n/a Binzel et al. (2004) Icarus 170, 259-294   3102 Krok (1981 QA)          Discovered 1981-Aug-21 by Brozek, L. at Klet Reference: DISCOVERY.DB Last Updated: 2003-08-29 [ show close-approach data ] [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2020-Dec-04 09:27 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin