******************************************************************************* 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 Fri Apr 19 04:16:57 2024 Pasadena, USA / Horizons ******************************************************************************* Target body name: Mercury Barycenter (199) {source: DE441} Center body name: Sun (10) {source: DE441} Center-site name: BODYCENTRIC ******************************************************************************* Start time : A.D. 2021-Jun-10 00:00:00.0000 UT Stop time : A.D. 2021-Jul-24 00:00:00.0000 UT Step-size : 1440 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, -695700.0 {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 : IAU_SUN {East-longitude positive} Center radii : 695700.0, 695700.0, 695700.0 km {Equator_a, b, pole_c} Target primary : Sun Vis. interferer : None 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.240418.p240712 EOP coverage : DATA-BASED 1962-JAN-20 TO 2024-APR-18. PREDICTS-> 2024-JUL-11 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 n.a. , 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 VmagSn VmagOb **************************************************************************** $$SOE 2021-Jun-10 00:00 0.46669841357016 0.0218326 38.8584630 38.8584629 2021-Jun-11 00:00 0.46657134834479 -0.4618071 38.8717865 38.8717864 2021-Jun-12 00:00 0.46616508003874 -0.9449300 38.9143960 38.9143958 2021-Jun-13 00:00 0.46548006427872 -1.4269868 38.9863003 38.9863002 2021-Jun-14 00:00 0.46451707831353 -1.9074116 39.0875147 39.0875145 2021-Jun-15 00:00 0.46327723304068 -2.3856134 39.2180592 39.2180590 2021-Jun-16 00:00 0.46176199016771 -2.8609670 39.3779585 39.3779583 2021-Jun-17 00:00 0.45997318475242 -3.3328032 39.5672403 39.5672401 2021-Jun-18 00:00 0.45791305343899 -3.8003987 39.7859339 39.7859337 2021-Jun-19 00:00 0.45558426878267 -4.2629656 40.0340676 40.0340674 2021-Jun-20 00:00 0.45298998013187 -4.7196388 40.3116663 40.3116660 2021-Jun-21 00:00 0.45013386161434 -5.1694640 40.6187471 40.6187469 2021-Jun-22 00:00 0.44702016785037 -5.6113832 40.9553153 40.9553150 2021-Jun-23 00:00 0.44365379809038 -6.0442195 41.3213576 41.3213573 2021-Jun-24 00:00 0.44004036954087 -6.4666610 41.7168353 41.7168350 2021-Jun-25 00:00 0.43618630069879 -6.8772421 42.1416745 42.1416741 2021-Jun-26 00:00 0.43209890555008 -7.2743242 42.5957547 42.5957543 2021-Jun-27 00:00 0.42778649949430 -7.6560749 43.0788950 43.0788946 2021-Jun-28 00:00 0.42325851781891 -8.0204451 43.5908365 43.5908361 2021-Jun-29 00:00 0.41852564744413 -8.3651460 44.1312220 44.1312216 2021-Jun-30 00:00 0.41359997246715 -8.6876247 44.6995710 44.6995706 2021-Jul-01 00:00 0.40849513371862 -8.9850399 45.2952502 45.2952498 2021-Jul-02 00:00 0.40322650206314 -9.2542388 45.9174384 45.9174379 2021-Jul-03 00:00 0.39781136447544 -9.4917365 46.5650857 46.5650853 2021-Jul-04 00:00 0.39226912094320 -9.6936992 47.2368661 47.2368656 2021-Jul-05 00:00 0.38662148891263 -9.8559356 47.9311230 47.9311225 2021-Jul-06 00:00 0.38089271022792 -9.9738974 48.6458080 48.6458076 2021-Jul-07 00:00 0.37510975324395 -10.0426962 49.3784136 49.3784132 2021-Jul-08 00:00 0.36930249995754 -10.0571399 50.1258993 50.1258990 2021-Jul-09 00:00 0.36350390458615 -10.0117957 50.8846158 50.8846155 2021-Jul-10 00:00 0.35775010608431 -9.9010879 51.6502282 51.6502279 2021-Jul-11 00:00 0.35208047280354 -9.7194367 52.4176449 52.4176447 2021-Jul-12 00:00 0.34653755323144 -9.4614453 53.1809583 53.1809581 2021-Jul-13 00:00 0.34116690308571 -9.1221416 53.9334067 53.9334065 2021-Jul-14 00:00 0.33601675687535 -8.6972749 54.6673688 54.6673687 2021-Jul-15 00:00 0.33113751254922 -8.1836653 55.3744033 55.3744032 2021-Jul-16 00:00 0.32658100241847 -7.5795912 56.0453467 56.0453466 2021-Jul-17 00:00 0.32239953355459 -6.8851954 56.6704817 56.6704816 2021-Jul-18 00:00 0.31864469734538 -6.1028721 57.2397831 57.2397832 2021-Jul-19 00:00 0.31536597096303 -5.2375916 57.7432436 57.7432437 2021-Jul-20 00:00 0.31260916181806 -4.2971110 58.1712675 58.1712676 2021-Jul-21 00:00 0.31041477641271 -3.2920177 58.5151139 58.5151140 2021-Jul-22 00:00 0.30881642226491 -2.2355657 58.7673536 58.7673537 2021-Jul-23 00:00 0.30783936949786 -1.1432860 58.9222968 58.9222969 2021-Jul-24 00:00 0.30749940133062 -0.0323810 58.9763451 58.9763451 $$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 'VmagSn VmagOb' = Magnitude of target centers' velocity with respect to the Sun ("VmagSn") and the observer ("VmagOb") at the time light left the target center to be observed (print time minus down-leg light-time). These are absolute values of the velocity vectors (total speeds) and do NOT indicate direction of motion. Units: 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 = '1' START_TIME = '2021-Jun-10' STOP_TIME = '2021-Jul-24' STEP_SIZE = '1 day' QUANTITIES = '20,22' CENTER = '@Sun'