******************************************************************************* Revised: April 12, 2021 Mercury 199 / 1 PHYSICAL DATA (updated 2024-Mar-04): Vol. Mean Radius (km) = 2439.4+-0.1 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) = 22031.86855 Equatorial radius, Re = 2440.53 km GM 1-sigma (km^3/s^2) = 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 Wed May 1 07:29:55 2024 Pasadena, USA / Horizons ******************************************************************************* Target body name: Mercury (199) {source: DE441} Center body name: Earth (399) {source: DE441} Center-site name: GEOCENTRIC ******************************************************************************* Start time : A.D. 2022-May-22 23:00:00.0000 UT Stop time : A.D. 2022-May-23 00:00:00.0000 UT Step-size : 10 minutes ******************************************************************************* Target pole/equ : IAU_MERCURY {West-longitude positive} Target radii : 2440.53, 2440.53, 2438.26 km {Equator_a, b, pole_c} Center geodetic : 0.0, 0.0, -6378.137 {E-lon(deg),Lat(deg),Alt(km)} Center cylindric: 0.0, 0.0, 0.0 {E-lon(deg),Dxy(km),Dz(km)} Center pole/equ : ITRF93 {East-longitude positive} Center radii : 6378.137, 6378.137, 6356.752 km {Equator_a, b, pole_c} Target primary : Sun Vis. interferer : MOON (R_eq= 1737.400) km {source: DE441} Rel. light bend : Sun {source: DE441} Rel. lght bnd GM: 1.3271E+11 km^3/s^2 Atmos refraction: NO (AIRLESS) RA format : HMS Time format : CAL Calendar mode : Mixed Julian/Gregorian EOP file : eop.240430.p240724 EOP coverage : DATA-BASED 1962-JAN-20 TO 2024-APR-30. PREDICTS-> 2024-JUL-23 Units conversion: 1 au= 149597870.700 km, c= 299792.458 km/s, 1 day= 86400.0 s Table cut-offs 1: Elevation (-90.0deg=NO ),Airmass (>38.000=NO), Daylight (NO ) Table cut-offs 2: Solar elongation ( 0.0,180.0=NO ),Local Hour Angle( 0.0=NO ) Table cut-offs 3: RA/DEC angular rate ( 0.0=NO ) ******************************************************************************* Date__(UT)__HR:MN delta deldot *************************************************** $$SOE 2022-May-22 23:00 0.55013083635945 -0.0426296 2022-May-22 23:10 0.55013069318124 -0.0287680 2022-May-22 23:20 0.55013060559556 -0.0149078 2022-May-22 23:30 0.55013057359668 -0.0010490 2022-May-22 23:40 0.55013059717888 0.0128083 2022-May-22 23:50 0.55013067633640 0.0266642 2022-May-23 00:00 0.55013081106351 0.0405187 $$EOE ******************************************************************************* Column meaning: TIME Times PRIOR to 1962 are UT1, a mean-solar time closely related to the prior but now-deprecated GMT. Times AFTER 1962 are in UTC, the current civil or "wall-clock" time-scale. UTC is kept within 0.9 seconds of UT1 using integer leap-seconds for 1972 and later years. Conversion from the internal Barycentric Dynamical Time (TDB) of solar system dynamics to the non-uniform civil UT time-scale requested for output has not been determined for UTC times after the next July or January 1st. Therefore, the last known leap-second is used as a constant over future intervals. Time tags refer to the UT time-scale conversion from TDB on Earth regardless of observer location within the solar system, although clock rates may differ due to the local gravity field and no analog to "UT" may be defined for that location. Any 'b' symbol in the 1st-column denotes a B.C. date. First-column blank (" ") denotes an A.D. date. 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. NOTE: "n.a." in output means quantity "not available" at the print-time. 'delta deldot' = Apparent range ("delta", light-time aberrated) and range-rate ("delta-dot") of the target center relative to the observer. A positive "deldot" means the target center is moving away from the observer, negative indicates movement toward the observer. Units: AU and KM/S 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 = '199' START_TIME = '2022-05-22 23:00' STOP_TIME = '2022-05-23' STEP_SIZE = '10 min' QUANTITIES = '20'