******************************************************************************* Revised: July 31, 2013 Mercury 199 / 1 PHYSICAL DATA (updated 2018-Aug-15): Vol. Mean Radius (km) = 2440+-1 Density (g cm^-3) = 5.427 Mass x10^23 (kg) = 3.302 Volume (x10^10 km^3) = 6.085 Sidereal rot. period = 58.6463 d Sid. rot. rate (rad/s)= 0.00000124001 Mean solar day = 175.9421 d Core radius (km) = ~1600 Geometric Albedo = 0.106 Surface emissivity = 0.77+-0.06 GM (km^3/s^2) = 22031.78 Equatorial radius, Re = 2440 km GM 1-sigma (km^3/s^2) = +-0.91 Mass ratio (Sun/plnt) = 6023682 Mom. of Inertia = 0.33 Equ. gravity m/s^2 = 3.701 Atmos. pressure (bar) = < 5x10^-15 Max. angular diam. = 11.0" Mean Temperature (K) = 440 Visual mag. V(1,0) = -0.42 Obliquity to orbit[1] = 2.11' +/- 0.1' Hill's sphere rad. Rp = 94.4 Sidereal orb. per. = 0.2408467 y Mean Orbit vel. km/s = 47.362 Sidereal orb. per. = 87.969257 d Escape vel. km/s = 4.435 Perihelion Aphelion Mean Solar Constant (W/m^2) 14462 6278 9126 Maximum Planetary IR (W/m^2) 12700 5500 8000 Minimum Planetary IR (W/m^2) 6 6 6 ******************************************************************************* ******************************************************************************* Ephemeris / WWW_USER Sun Feb 16 20:12:27 2020 Pasadena, USA / Horizons ******************************************************************************* Target body name: Mercury (199) {source: DE431mx} Center body name: Solar System Barycenter (0) {source: DE431mx} Center-site name: BODY CENTER ******************************************************************************* Start time : A.D. 2020-Jan-02 00:00:00.0000 TDB Stop time : A.D. 2020-Jan-02 00:01:00.0000 TDB Step-size : 60 minutes ******************************************************************************* Center geodetic : 0.00000000,0.00000000,0.0000000 {E-lon(deg),Lat(deg),Alt(km)} Center cylindric: 0.00000000,0.00000000,0.0000000 {E-lon(deg),Dxy(km),Dz(km)} Center radii : (undefined) Output units : KM-D Output type : GEOMETRIC cartesian states Output format : 3 (position, velocity, LT, range, range-rate) Reference frame : ICRF/J2000.0 Coordinate systm: Earth Mean Equator and Equinox of Reference Epoch ******************************************************************************* JDTDB X Y Z VX VY VZ LT RG RR ******************************************************************************* $$SOE 2458850.500000000 = A.D. 2020-Jan-02 00:00:00.0000 TDB X =-6.706768603511997E+06 Y =-6.044456979601756E+07 Z =-3.175166446027326E+07 VX= 3.346870048130878E+06 VY=-1.701434983573897E+04 VZ=-3.560819057750839E+05 LT= 2.648643948087839E-03 RG= 6.860535663433631E+07 RR=-1.473946817886314E+05 $$EOE ******************************************************************************* Coordinate system description: NOTE: The ICRF is quasar-based; the EME description below is given as a dynamical explanation of the previous system to which the ICRF was closely aligned. ICRF ("Earth Mean Equator and Equinox of Reference Epoch") Reference epoch: J2000.0 XY-plane: plane of the Earth's mean equator at the reference epoch X-axis : out along ascending node of instantaneous plane of the Earth's orbit and the Earth's mean equator at the reference epoch Z-axis : along the Earth mean north pole at the reference epoch Symbol meaning [1 day=86400.0 s]: JDTDB Julian Day Number, Barycentric Dynamical Time X X-component of position vector (km) Y Y-component of position vector (km) Z Z-component of position vector (km) VX X-component of velocity vector (km/day) VY Y-component of velocity vector (km/day) VZ Z-component of velocity vector (km/day) LT One-way down-leg Newtonian light-time (day) RG Range; distance from coordinate center (km) RR Range-rate; radial velocity wrt coord. center (km/day) Geometric states/elements have no aberrations applied. Computations by ... Solar System Dynamics Group, Horizons On-Line Ephemeris System 4800 Oak Grove Drive, Jet Propulsion Laboratory Pasadena, CA 91109 USA Information: http://ssd.jpl.nasa.gov/ Connect : telnet://ssd.jpl.nasa.gov:6775 (via browser) http://ssd.jpl.nasa.gov/?horizons telnet ssd.jpl.nasa.gov 6775 (via command-line) Author : Jon.D.Giorgini@jpl.nasa.gov ******************************************************************************* !$$SOF command = 199 TABLE_TYPE = 'VECTORS' REF_PLANE = 'FRAME' START_TIME = '2020-Jan-02 00:00:00.0000' STOP_TIME = '2020-Jan-02 00:01:00.0000' STEP_SIZE = '1 hours' OUT_UNITS = 'KM-D' CENTER = 500@0