+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   162173 Ryugu (1999 JU3) Classification: Apollo [NEO, PHA]          SPK-ID: 2162173 [ 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 129 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1903011700844365 3.7005e-08   a 1.18967955797191 3.8198e-09 au q .9632821460643204 4.4899e-08 au i 5.881930011476855 2.4856e-06 deg node 251.5783110723126 3.2521e-05 deg peri 211.4853312065659 3.3534e-05 deg M 193.6376572277171 1.6097e-05 deg tp 2459219.526141589393 (2021-Jan-05.02614159) 2.1139e-05 TDB period 473.9618934082372 1.30 2.2827e-06 6.25e-09 d yr n .7595547342662029 3.6581e-09 deg/d Q 1.4160769698795 4.5467e-09 au Additional Model Parameters  Parameter Value Uncertainty (1-sigma)  A2 [EST] -2.196402439893876E-14 1.187E-14 ALN [SET] 1. n/a NK [SET] 0. n/a NM [SET] 2. n/a R0 [SET] 1. n/a   Orbit Determination Parameters    # obs. used (total)      840      data-arc span      12566 days (34.40 yr)      first obs. used      1986-04-14      last obs. used      2020-09-08      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .37902      source      ORB      producer      Otto Matic      solution date      2020-Sep-15 06:58:26   Additional Information  Earth MOID = .000968354 au   Jupiter MOID = 3.69764 au   T_jup = 5.308   Nongravitational accels. using nonstandard g(r) = (1 au/ r)^2  [ 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 19.3   n/a MPO385718   rotation period rot_per 7.627 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: [Abe, M.; Kawakami, K.; Hasegawa, S.; Kuroda, D.; Yoshikawa, M.; et al. (2008) Lunar & Planetary Sci. XXXIX. No. 1391, p. 1594.] [Muller, T.G.; Durech, J.; Hasegawa, S.; Abe, M.; et al. (2011) Astron. Astrophys. 525, A145.] [Kim, M.-J.; Choi, Y.-J.; Moon, H.-K.; Ishiguro, M.; et al. (2013) Astron. Astrophys. 550, L11.] [Moskovitz, N.A.; Abe, S.; Pan, K.-S.; Osip, D.J.; et al. (2013) Icarus 224, 24.] [Muller, T.G.; Durech, J.; Ishiguro, M.; Mueller, M.; et al. (2017) Astron. Astrophys. 599, A103.] SMASSII spectral type spec_B Cg   n/a Binzel et al. (2001) Icarus 151, 139-149   162173 Ryugu           Discovered 1999 May 10 by the Lincoln Laboratory Near-Earth Asteroid Research Team at Socorro. Ryugu is the undersea palace of the Dragon God. In a Japanese legend, a fisherman was rewarded with a visit to Ryugu and brought back a box with a secret. The spaceprobe Hayabusa 2 will visit this asteroid and bring back a capsule containing surface samples. NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character) Reference: MPC batch dated 2015-09-28 Last Updated: 2015-10-05 [ show close-approach data ] [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2020-Sep-22 21:54 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin