+ 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 2459200.5 (2020-Dec-17.0) TDB Reference: JPL 221 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1909943690962667 1.3812e-08   a 1.190568663916711 3.8187e-09 au q .9631767530861532 1.7603e-08 au i 5.88371604159193 1.3437e-06 deg node 251.5358517865301 1.0411e-05 deg peri 211.443709985476 1.2738e-05 deg M 345.6399295403424 6.5879e-06 deg tp 2459219.427103995259 (2021-Jan-04.92710400) 8.6157e-06 TDB period 474.4933151571533 1.30 2.2829e-06 6.25e-09 d yr n .7587040501946104 3.6503e-09 deg/d Q 1.417960574747268 4.5481e-09 au Additional Model Parameters  Parameter Value Uncertainty (1-sigma)  A2 [EST] -2.123466398767116E-14 1.075E-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)      1983      data-arc span      12785 days (35.00 yr)      first obs. used      1986-04-14      last obs. used      2021-04-15      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .31496      source      ORB      producer      Otto Matic      solution date      2021-Apr-16 06:27:07   Additional Information  Earth MOID = .00049099 au   Jupiter MOID = 3.69587 au   T_jup = 5.305   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 19.39   n/a E2021B55   rotation period rot_per 7.63262 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: [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.] [Watanabe, S.; Hirabayashi, M.; Hirata, N.; Hirata, Na.; et al. (2019) Science 364, 267-272.] [Warner, B.D.; Stephens, R.D. (2021) Minor Planet Bull. 48-1, submitted. (NEA) http://www.planetarysciences.org/lightcurves.html] 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 ] 2021-Apr-18 07:07 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin