API VERSION: 1.2 API SOURCE: NASA/JPL Horizons API ******************************************************************************* Ephemeris / API_USER Thu Jul 4 00:27:31 2024 Pasadena, USA / Horizons ******************************************************************************* Target body name: 99942 Apophis (2004 MN4) {source: JPL#218} Center body name: Solar System Barycenter (0) {source: DE441} Center-site name: BODY CENTER ******************************************************************************* Start time : A.D. 2023-Feb-25 00:00:00.0000 TDB Stop time : A.D. 2023-Feb-26 00:00:00.0000 TDB Step-size : 1 calendar years ******************************************************************************* 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 : (undefined) Keplerian GM : 2.9630927493968080E-04 au^3/d^2 Small perturbers: Yes {source: SB441-N16} 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 ******************************************************************************* Initial IAU76/J2000 heliocentric ecliptic osculating elements (au, days, deg.): EPOCH= 2459215.5 ! 2021-Jan-01.00 (TDB) Residual RMS= .17952 EC= .1915216892529348 QR= .7458270479403062 TP= 2459101.039422418 OM= 204.0389271089114 W= 126.6520518833791 IN= 3.336751319526047 Equivalent ICRF heliocentric cartesian coordinates (au, au/d): X=-4.098530837957945E-01 Y= 9.070198867765817E-01 Z= 3.267919471926086E-01 VX=-1.507552412223498E-02 VY=-3.713559924880165E-03 VZ=-1.761867984500986E-03 Asteroid physical parameters (km, seconds, rotational period in hours): GM= n.a. RAD= .170 ROTPER= 30.56 H= 19.09 G= .240 B-V= n.a. Non-default Earth gravity model (EOBL_LIM= au): EOBL_LIM= 1.000 EOBL_MOD = 2x0 (J2 only) Asteroid non-gravitational force model (AMRAT= m^2/kg;A1,A2,A3=au/d^2;R0=au): AMRAT= 0. A1= 4.999999873689E-13 A2= -2.901092102547E-14 A3= 0. Non-standard or simulated/proxy model: ALN= 1. NK= 0. NM= 2. NN= 5.093 R0= 1. ******************************************************************************* JDTDB EC QR IN OM W Tp N MA TA A AD PR ******************************************************************************* $$SOE 2460000.500000000 = A.D. 2023-Feb-25 00:00:00.0000 TDB EC= 1.979409652905069E-01 QR= 7.495596383038445E-01 IN= 3.352861794779940E+00 OM= 2.035961161561415E+02 W = 1.252187949336197E+02 Tp= 2460071.408668024000 N = 1.091680288553880E+00 MA= 2.825904048303408E+02 TA= 2.598132426957505E+02 A = 9.345442241359904E-01 AD= 1.119528809968136E+00 PR= 3.297668775140042E+02 $$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 *******************************************************************************