+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   2180 Marjaleena (1940 RJ) Classification: Main-belt Asteroid          SPK-ID: 2002180 [ 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 41 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .07929561812867721 3.5525e-08   a 3.013107214477866 1.5665e-08 au q 2.774181015417867 1.0634e-07 au i 9.249906258361403 4.0024e-06 deg node 233.282496209254 2.418e-05 deg peri 88.51539244138527 3.5327e-05 deg M 116.999542121625 2.6416e-05 deg tp 2458379.628154857499 (2018-Sep-18.12815486) 0.00013998 TDB period 1910.382384393864 5.23 1.4898e-05 4.079e-08 d yr n .188443948677962 1.4695e-09 deg/d Q 3.252033413537865 1.6907e-08 au   Orbit Determination Parameters    # obs. used (total)      2772      data-arc span      25188 days (68.96 yr)      first obs. used      1951-12-01      last obs. used      2020-11-16      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .40705      source      ORB      producer      Otto Matic      solution date      2020-Dec-18 02:04:50   Additional Information  Earth MOID = 1.78194 au   Jupiter MOID = 1.99365 au   T_jup = 3.224  [ 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 11.0   n/a MPO337265   diameter diameter 21.357 km 0.167 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   rotation period rot_per 7.717 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: [Behrend, R. (2014) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html] [Waszczak, A.; Chang, C.-K.; Ofeck, E.O.; Laher, F.; et al. (2015) Astron. J. 150, A75.] [Polakis, T. (2020) Minor Planet Bull. 47, 94-101.] geometric albedo albedo 0.154   0.017 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   2180 Marjaleena (1940 RJ)          Discovered 1940-Sep-08 by Alikoski, H. at Turku Reference: DISCOVERY.DB Last Updated: 2003-08-29 [ show close-approach data ] Alternate Designations  1940 RJ = 1950 NQ1 = 1970 JL = 1970 JR = 1971 OL1 = 1976 NM = 1977 TT3  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Jan-25 20:13 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin