+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   101955 Bennu (1999 RQ36) Classification: Apollo [NEO, PHA]          SPK-ID: 2101955 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] [ show orbit diagram ] Orbital Elements at Epoch 2455562.5 (2011-Jan-01.0) TDB Reference: JPL 97 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .2037451084785423 2.2082e-08   a 1.126391025934071 4.0261e-11 au q .8968943641658774 2.486e-08 au i 6.034939533607825 2.8213e-06 deg node 2.060867329373625 3.9444e-06 deg peri 66.22306846088361 6.0706e-06 deg M 101.7039479473255 2.6478e-06 deg tp 2455439.141945784743 (2010-Aug-30.64194578) 3.2088e-06 TDB period 436.6487281348487 1.20 2.3411e-08 6.41e-11 d yr n .8244613502889271 4.4203e-11 deg/d Q 1.355887687702265 4.8464e-11 au Additional Model Parameters  Parameter Value Uncertainty (1-sigma)  A2 [EST] -4.614425168815923E-14 2.533E-16 ALN [SET] 1 n/a AMRAT [SET] 3.07E-6 n/a NK [SET] 0 n/a NM [SET] 2.25 n/a NN [SET] 0 n/a R0 [SET] 1 n/a   Orbit Determination Parameters    # obs. used (total)      518      # delay obs. used      22      # Doppler obs. used      7      data-arc span      6821 days (18.67 yr)      first obs. used      1999-09-11      last obs. used      2018-05-15      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .27502      source      ORB      producer      Otto Matic      solution date      2018-May-19 06:45:18   Additional Information  Earth MOID = .0032228 au   Jupiter MOID = 3.87795 au   T_jup = 5.525   Nongravitational accels. using nonstandard g(r) = (1 au/ r)^2.25  [ hide covariance matrix ] Orbit Covariance (7×7)   e q tp node peri i A2 e 4.876126089505472E-16 -5.489515949261297E-16 6.712480293858912E-14 3.798365955673847E-14 8.53293802793787E-14 -6.113133517034296E-14 1.025860986607549E-24 q -5.489515949261297E-16 6.180075423658981E-16 -7.556465812714661E-14 -4.277275824120684E-14 -9.604878246862599E-14 6.881233572121735E-14 -1.149264057030884E-24 tp 6.712480293858912E-14 -7.556465812714661E-14 1.029612448103599E-11 1.601421539267492E-12 1.654024367138294E-11 -8.581564399530374E-12 2.833860998250541E-22 node 3.798365955673847E-14 -4.277275824120684E-14 1.601421539267492E-12 1.555863300581238E-11 -9.967239111631652E-12 -4.225132119600793E-12 -3.998065418944505E-22 peri 8.53293802793787E-14 -9.604878246862599E-14 1.654024367138294E-11 -9.967239111631652E-12 3.685213586142038E-11 -1.142699730568605E-11 8.152756993132622E-22 i -6.113133517034296E-14 6.881233572121735E-14 -8.581564399530374E-12 -4.225132119600793E-12 -1.142699730568605E-11 7.959683554671319E-12 -2.441090611318138E-22 A2 1.025860986607549E-24 -1.149264057030884E-24 2.833860998250541E-22 -3.998065418944505E-22 8.152756993132622E-22 -2.441090611318138E-22 6.416380063608494E-32 [ 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 20.19   0.06 Hergenrother, C.W. et al. Icarus 226, 663-670 (2013)   magnitude slope G -0.08   0.02 Hergenrother, C.W. et al. Icarus 226, 663-670 (2013)   diameter diameter 0.492 km 0.020 Nolan, M.C., et al., Icarus 226, 629-640 (2013)   extent extent 0.565 x 0.535 x 0.508 km 0.010 x 0.010 x 0.052 Nolan, M.C., et al., Icarus 226, 629-640 (2013)   GM GM 5.2e-9 km^3/s^2 0.9e-9 Chesley, S.R., et al., Icarus 235, 5-22 (2014)   bulk density density 1.26 g/cm^3 0.07 Chesley, S.R., et al., Icarus 235, 5-22 (2014)   rotation period rot_per 4.297 h 0.002 Nolan, M.C., et al., Icarus 226, 629-640 (2013)   pole direction pole 87/-65   4 Nolan, M.C., et al., Icarus 226, 629-640 (2013)   geometric albedo albedo 0.046   0.005 Emery, J.P., et al., Icarus 234, 17-35 (2014)   B-V BV 0.64   0.04 Hergenrother, C.W. et al. Icarus 226, 663-670 (2013)   U-B UB 0.16   0.05 Hergenrother, C.W. et al. Icarus 226, 663-670 (2013)   I-R IR -0.33   0.06 Hergenrother, C.W. et al. Icarus 226, 663-670 (2013)   SMASSII spectral type spec_B B   n/a Clark, B.E., et al., Icarus 216, 462-475 (2011)   101955 Bennu           Discovered 1999 Sept. 11 by the Lincoln Laboratory Near-Earth Asteroid Research Team at Socorro. Bennu was an Egyptian mythological figure associated with Osiris, Atum and Ra. This minor planet is the target of the OSIRIS-REx sample return mission. OSIRIS-REx's Touch-and-Go Sampler evokes Bennu's image as a heron. Name suggested by Michael Toler Puzio (b. 2004) via a naming contest for students. 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 2013-04-25 Last Updated: 2013-04-29 [ show close-approach data ] [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Jan-28 01:15 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin