+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   20461 Dioretsa (1999 LD31) Classification: Centaur          SPK-ID: 2020461 [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ] [ show orbit diagram ] Orbital Elements at Epoch 2459200.5 (2020-Dec-17.0) TDB Reference: JPL 7 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .9005636744648127 3.2626e-06   a 23.89275004388222 0.00079672 au q 2.375807271294334 1.5165e-06 au i 160.4308914475279 2.2448e-05 deg node 297.859541044166 7.8644e-05 deg peri 103.1048298502124 0.00012598 deg M 64.89789213707344 0.003244 deg tp 2451510.510851675385 (1999-Nov-28.01085168) 0.0003838 TDB period 42657.71972300149 116.79 2.1337 0.005842 d yr n .008439269664146726 4.2212e-07 deg/d Q 45.40969281647011 0.0015142 au   Orbit Determination Parameters    # obs. used (total)      278      data-arc span      927 days (2.54 yr)      first obs. used      1998-06-16      last obs. used      2000-12-29      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      2      norm. resid. RMS      .48507      source      ORB      producer      Otto Matic      solution date      2021-Apr-13 03:21:44   Additional Information  Earth MOID = 1.46601 au   Jupiter MOID = .175405 au   T_jup = -1.538  [ show covariance matrix ] [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes absolute magnitude H 13.8   n/a PDS3 (MPO 7841)   20461 Dioretsa           Discovered 1999 June 8 by the Lincoln Laboratory Near Earth Asteroid Research Team at Socorro. As befits the first numbered asteroid in a retrograde orbit, Dioretsa is the word asteroid spelled backwards. The name was suggested independently by K. Kitterman and S. Cooksey of Flagstaff, Arizona. NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character) Reference: 20030501/MPCPages.arc Last Updated: 2003-10-02 [ show close-approach data ] [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Apr-15 00:32 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin