API VERSION: 1.2
API SOURCE: NASA/JPL Horizons API


Statistical uncertainties not available for object due to:
  truncated database EST list: +

*******************************************************************************
 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
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Ephemeris / API_USER Sun Jul 12 11:58:14 2026 Pasadena, USA      / Horizons
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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. 2024-Jan-01 00:00:00.0000 TDB
Stop  time      : A.D. 2024-Jan-01 00:00:00.0000 TDB
Step-size       : DISCRETE TIME-LIST
*******************************************************************************
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}
Output units    : AU-D
Calendar mode   : Mixed Julian/Gregorian
Output type     : GEOMETRIC cartesian states
Output format   : 3 (position, velocity, LT, range, range-rate)
Reference frame : Ecliptic of J2000.0
*******************************************************************************
            JDTDB,            Calendar Date (TDB),                      X,                      Y,                      Z,                     VX,                     VY,                     VZ,                     LT,                     RG,                     RR,
**************************************************************************************************************************************************************************************************************************************************************************
$$SOE
2460310.500000000, A.D. 2024-Jan-01 00:00:00.0000, -8.949052809876745E-01,  5.353223139378872E-01,  5.982667219505702E-02, -1.167459005576071E-02, -1.287494949256736E-02, -1.317155627348354E-03,  6.032596418244626E-03,  1.044511690908904E+00,  3.328448625691669E-03,
$$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
      X      X-component of position vector (au)
      Y      Y-component of position vector (au)
      Z      Z-component of position vector (au)
      VX     X-component of velocity vector (au/day)                           
      VY     Y-component of velocity vector (au/day)                           
      VZ     Z-component of velocity vector (au/day)                           
      LT     One-way down-leg Newtonian light-time (day)
      RG     Range; distance from coordinate center (au)
      RR     Range-rate; radial velocity wrt coord. center (au/day)

ABERRATIONS AND CORRECTIONS

 Geometric state vectors 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/horizons_batch.txt
                  scripts        https://ssd.jpl.nasa.gov/ftp/ssd/SCRIPTS
    Inquiries   : Jon.D.Giorgini@jpl.nasa.gov
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