+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   11885 Summanus (1990 SS) Classification: Apollo [NEO]          SPK-ID: 2011885 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] [ show orbit diagram ] Orbital Elements at Epoch 2459396.5 (2021-Jul-01.0) TDB Reference: JPL 69 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .4744267778382812 3.6696e-08   a 1.7038070560964 1.9987e-09 au q .8954753644144572 6.2518e-08 au i 19.42781080589474 1.4107e-05 deg node 359.7900204368338 1.0419e-05 deg peri 116.1974627571214 1.5697e-05 deg M 245.5307698066716 7.2297e-06 deg tp 2459654.794588268925 (2022-Mar-16.29458827) 1.6591e-05 TDB period 812.3235529737369 2.22 1.4294e-06 3.913e-09 d yr n .4431731650302636 7.7983e-10 deg/d Q 2.512138747778342 2.947e-09 au   Orbit Determination Parameters    # obs. used (total)      341      data-arc span      10827 days (29.64 yr)      first obs. used      1990-09-25      last obs. used      2020-05-17      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .47174      source      ORB      producer      Otto Matic      solution date      2021-May-04 01:03:34   Additional Information  Earth MOID = .0680464 au   Jupiter MOID = 2.76177 au   T_jup = 4.004  [ 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 18.42   n/a E2021B10   diameter diameter 1.298 km 0.446 urn:nasa:pds:neowise_diameters_albedos::2.0[neos] (http://adsabs.harvard.edu/abs/2012ApJ...760L..12M)   rotation period rot_per 7.368 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List: [Skiff, B.A.; McLelland, K.P.; Sanborn, J.J.; Pravec, P.; Koehn, B.W. (2019) Minor Plantet Bull. 46, 238-265.] geometric albedo albedo 0.033   0.029 urn:nasa:pds:neowise_diameters_albedos::2.0[neos] (http://adsabs.harvard.edu/abs/2012ApJ...760L..12M)   11885 Summanus           Discovered 1990 Sept. 25 by Spacewatch at Kitt Peak. Summanus was the Etruscan or Roman deity responsible for nocturnal lightning and thunder, as Jupiter was in daytime. This was the first earth-approacher discovered automatically by software and (lightning-fast) electronic computer; J. V. Scotti used D. L. Rabinowitz's Moving Object Detection Program at the telescope. NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character) Reference: 20100923/MPCPages.arc Last Updated: 2010-12-06 [ show close-approach data ] Alternate Designations  1990 SS = 2019 UH87  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Jul-25 12:19 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin