+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   2608 Seneca (1978 DA) Classification: Amor [NEO]          SPK-ID: 2002608 [ 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 19 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .5709673236567876 1.5378e-07   a 2.516282772678057 2.8297e-08 au q 1.079567532398386 3.8354e-07 au i 14.67274945506941 2.2318e-05 deg node 167.3469303119492 4.0596e-05 deg peri 37.38316178994204 0.00012299 deg M 240.1293104884265 0.0002054 deg tp 2459485.954013516919 (2021-Sep-28.45401352) 0.00083645 TDB period 1457.933090884721 3.99 2.4593e-05 6.733e-08 d yr n .2469249118843584 4.1653e-09 deg/d Q 3.952998012957728 4.4454e-08 au   Orbit Determination Parameters    # obs. used (total)      71      data-arc span      14778 days (40.46 yr)      first obs. used      1978-02-17      last obs. used      2018-08-04      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      1      norm. resid. RMS      .59421      source      ORB      producer      Otto Matic      solution date      2018-Aug-05 06:22:28   Additional Information  Earth MOID = .132428 au   Jupiter MOID = 1.13883 au   T_jup = 3.172  [ 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 17.52   n/a PDS3 (MPC 17266)   diameter diameter 0.9 km n/a Hazards due to Comets and Asteroids (1994), Ed. T. Gehrels, pp.540-543   rotation period rot_per 8. h n/a LCDB (Rev. 2019-August); 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: [Degewij, J. (1978) Messenger 13, 5; IAUC 3193.] geometric albedo albedo 0.21   n/a Hazards due to Comets and Asteroids (1994), Ed. T. Gehrels, pp.540-543   B-V BV 0.826   0.020 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=4; phase (min.=22.10, mean=23.28, max.=26.12) deg. U-B UB 0.454   0.052 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=4; phase (min.=22.22, mean=23.41, max.=26.12) deg. Tholen spectral type spec_T S   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 2 color indices 2608 Seneca (1978 DA)          Discovered 1978-Feb-17 by Schuster, H.-E. at La Silla 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-01 00:35 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin