******************************************************************************* Revised: Aug 11, 2021 101955 Bennu (1999 RQ36) 2101955 *SPECIAL* Soln.date: 2021-Jan-07_11:18:06 # obs: 554 (1999-2020) IAU76/J2000 helio. ecliptic osc. elements (au, days, deg., period=Julian yrs): EPOCH= 2455562.5 ! 2011-Jan-01.00 (TDB) Residual RMS= .23164 EC= .2037450762416414 QR= .8968944004459729 TP= 2455439.14194087 OM= 2.060866195696420 W= 66.22306084084298 IN= 6.0349437702479403 A= 1.1263910258948120 MA= 101.7039520024729 ADIST= 1.355887651343651 PER= 1.19548 N= 0.824461327 ANGMOM= .017873901 DAN= 0.99768 DDN= 1.17626 L= 68.16622425 B= 5.521044 MOID= .0032228 TP= 2010-Aug-30.6419408992 Asteroid physical parameters (km, seconds, rotational period in hours): GM= n.a. RAD= .241 ROTPER= 4.2960610 H= 20.21 G= -0.031 B-V= 0.64 ALBEDO= .044 STYP= B Asteroid non-gravitational force model (AMRAT= m^2/kg;A1,A2,A3=au/d^2;R0=au): AMRAT= .00000026 A1= 0. A2= 0. A3= 0. Yarkovsky acceleration: RHO= 1191.5349121 This pre-computed trajectory of asteroid (101955) Bennu, covering 1900 to 2136 is based on ground-based optical and radar astrometry as well as pseudo-range measurements from the OSIRIS-REx mission. The trajectory accounts for the gravity of the Sun, the planets, Pluto, the Moon and 343 small-body perturbers, relativistic effect, the Yarkovsky effect, and other solar radiation perturbations. Full details are provided in Farnocchia et al. (2021): https://doi.org/10.1016/j.icarus.2021.114594 It may be used to generate ephemerides relative to the SPACECRAFT-BASED Bennu solution by specifying coordinate center as "@2101955", or extended physical ephemerides of Bennu such as sub-observer/solar latitude and longitude. Trajectory name Start (TDB) Stop (TDB) ---------------------------------------------- ----------- ----------- sb-101955-118_long 1900-Jan-01 2135-Oct-01 Due to the non-standard dynamical models enabled by extensive high-precision spacecraft data, Horizons won't generate new SPK files for Bennu. However, the final reconstructed mission SPK can be downloaded for use here: https://ssd.jpl.nasa.gov/ftp/xfr/sb-101955-118_long.bsp ASTEROID comments: 1: soln ref.= JPL#118, PHA OCC=0 radar(58 delay, 7 Dop.) 2: source=ORB; See Farnocchia et al. 2021 ******************************************************************************* ******************************************************************************* Ephemeris / WWW_USER Fri Apr 19 22:04:48 2024 Pasadena, USA / Horizons ******************************************************************************* Target body name: 101955 Bennu (1999 RQ36) (2101955) {source: ORX_merged_DE424} Center body name: Sun (10) {source: ORX_merged_DE424} Center-site name: BODY CENTER ******************************************************************************* Start time : A.D. 2135-Aug-30 00:00:00.0000 TDB Stop time : A.D. 2135-Sep-30 00:00:00.0000 TDB Step-size : 1 calendar months ******************************************************************************* Center geodetic : 0.0, 0.0, 0.0 {E-lon(deg),Lat(deg),Alt(km)} Center cylindric: 0.0, 0.0, 0.0 {E-lon(deg),Dxy(km),Dz(km)} Center radii : 695700.0, 695700.0, 695700.0 km {Equator_a, b, pole_c} Keplerian GM : 2.9591220828411951E-04 au^3/d^2 Output units : AU-D, deg, Julian Day Number (Tp) Calendar mode : Mixed Julian/Gregorian Output type : GEOMETRIC osculating elements Output format : 10 Reference frame : Ecliptic of J2000.0 ******************************************************************************* JDTDB EC QR IN OM W Tp N MA TA A AD PR ******************************************************************************* $$SOE 2501093.500000000 = A.D. 2135-Aug-30 00:00:00.0000 TDB EC= 1.974204469967772E-01 QR= 8.912761035284095E-01 IN= 6.245780825804006E+00 OM= 3.175896516269907E-01 W = 7.072012422410360E+01 Tp= 2501180.149342771620 N = 8.422050027195384E-01 MA= 2.870234900352290E+02 TA= 2.643266515816225E+02 A = 1.110514341155699E+00 AD= 1.329752578782989E+00 PR= 4.274493725845073E+02 2501124.500000000 = A.D. 2135-Sep-30 00:00:00.0000 TDB EC= 2.065098113988148E-01 QR= 9.147538786854018E-01 IN= 6.603896928237784E+00 OM= 1.730534129768995E-01 W = 6.059905980860130E+01 Tp= 2501172.241014567204 N = 7.962693994313008E-01 MA= 3.219852910023058E+02 TA= 3.040432513779947E+02 A = 1.152823175164885E+00 AD= 1.390892471644369E+00 PR= 4.521082943249025E+02 $$EOE ******************************************************************************* TIME Barycentric Dynamical Time ("TDB" or T_eph) output was requested. This continuous coordinate time is equivalent to the relativistic proper time of a clock at rest in a reference frame co-moving with the solar system barycenter but outside the system's gravity well. It is the independent variable in the solar system relativistic equations of motion. TDB runs at a uniform rate of one SI second per second and is independent of irregularities in Earth's rotation. CALENDAR SYSTEM Mixed calendar mode was active such that calendar dates after AD 1582-Oct-15 (if any) are in the modern Gregorian system. Dates prior to 1582-Oct-5 (if any) are in the Julian calendar system, which is automatically extended for dates prior to its adoption on 45-Jan-1 BC. The Julian calendar is useful for matching historical dates. The Gregorian calendar more accurately corresponds to the Earth's orbital motion and seasons. A "Gregorian-only" calendar mode is available if such physical events are the primary interest. REFERENCE FRAME AND COORDINATES Ecliptic at the standard reference epoch Reference epoch: J2000.0 X-Y plane: adopted Earth orbital plane at the reference epoch Note: IAU76 obliquity of 84381.448 arcseconds wrt ICRF X-Y plane X-axis : ICRF Z-axis : perpendicular to the X-Y plane in the directional (+ or -) sense of Earth's north pole at the reference epoch. Symbol meaning [1 au= 149597870.700 km, 1 day= 86400.0 s]: JDTDB Julian Day Number, Barycentric Dynamical Time EC Eccentricity, e QR Periapsis distance, q (au) IN Inclination w.r.t X-Y plane, i (degrees) OM Longitude of Ascending Node, OMEGA, (degrees) W Argument of Perifocus, w (degrees) Tp Time of periapsis (Julian Day Number) N Mean motion, n (degrees/day) MA Mean anomaly, M (degrees) TA True anomaly, nu (degrees) A Semi-major axis, a (au) AD Apoapsis distance (au) PR Sidereal orbit period (day) ABERRATIONS AND CORRECTIONS Geometric osculating elements have NO corrections or aberrations applied. Computations by ... Solar System Dynamics Group, Horizons On-Line Ephemeris System 4800 Oak Grove Drive, Jet Propulsion Laboratory Pasadena, CA 91109 USA General site: https://ssd.jpl.nasa.gov/ Mailing list: https://ssd.jpl.nasa.gov/email_list.html System news : https://ssd.jpl.nasa.gov/horizons/news.html User Guide : https://ssd.jpl.nasa.gov/horizons/manual.html Connect : browser https://ssd.jpl.nasa.gov/horizons/app.html#/x API https://ssd-api.jpl.nasa.gov/doc/horizons.html command-line telnet ssd.jpl.nasa.gov 6775 e-mail/batch https://ssd.jpl.nasa.gov/ftp/ssd/hrzn_batch.txt scripts https://ssd.jpl.nasa.gov/ftp/ssd/SCRIPTS Author : Jon.D.Giorgini@jpl.nasa.gov ******************************************************************************* !$$SOF COMMAND = 'Bennu' TABLE_TYPE = 'ELEMENTS' START_TIME = '2135-Aug-30' STOP_TIME = '2135-Sep-30' STEP_SIZE = '1 month' CENTER = '@sun' OUT_UNITS = 'AU-D'