+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   1161 Thessalia (1929 SF) Classification: Main-belt Asteroid          SPK-ID: 2001161 [ 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 42 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .08803183821163053 4.1446e-08   a 3.169590168925892 1.6346e-08 au q 2.890565319977834 1.3352e-07 au i 9.39650852252448 3.9706e-06 deg node 72.56420938188438 2.6368e-05 deg peri 310.1720331056558 3.3556e-05 deg M 26.73656708849001 2.0083e-05 deg tp 2458847.424306041133 (2019-Dec-29.92430604) 0.00011515 TDB period 2061.119127328635 5.64 1.5944e-05 4.365e-08 d yr n .1746623934670807 1.3511e-09 deg/d Q 3.448615017873951 1.7785e-08 au   Orbit Determination Parameters    # obs. used (total)      2516      data-arc span      33272 days (91.09 yr)      first obs. used      1929-09-29      last obs. used      2020-11-02      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .45112      source      ORB      producer      Otto Matic      solution date      2020-Dec-18 01:58:49   Additional Information  Earth MOID = 1.90613 au   Jupiter MOID = 1.98962 au   T_jup = 3.176  [ 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 11.2   n/a MPO502164   diameter diameter 21.498 km 0.184 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   geometric albedo albedo 0.065   0.010 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2012ApJ...759L...8M)   1161 Thessalia (1929 SF)          Discovered 1929-Sep-29 by Reinmuth, K. at Heidelberg Reference: DISCOVERY.DB Last Updated: 2003-08-29 Alternate Designations  1929 SF = 1931 BB  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-Jan-28 07:05 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin