******************************************************************************* 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 Sat Jan 16 01:51:56 2021 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 ******************************************************************************* 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: International Celestial Reference Frame (ICRF) The ICRF is an adopted reference frame whose axes are defined relative to fixed extragalactic radio sources distributed across the sky. The ICRF was aligned with the prior FK5/J2000 dynamical system at the ~0.02 arcsecond level but is not identical and has no associated standard 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 : https://ssd.jpl.nasa.gov/ Documentation: https://ssd.jpl.nasa.gov/?horizons_doc Connect : https://ssd.jpl.nasa.gov/?horizons (browser) telnet ssd.jpl.nasa.gov 6775 (command-line) e-mail command interface available Script and CGI interfaces available 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