mirrored file at http://SaturnianCosmology.Org/ For complete access to all the files of this collection see http://SaturnianCosmology.org/search.php ========================================================== _________________________________________________________________ Mars Fact Sheet _________________________________________________________________ [1][Global view of Mars] _________________________________________________________________ Mars/Earth Comparison _________________________________________________________________ Bulk parameters Mars Earth Ratio (Mars/Earth) Mass (10^24 kg) 0.64185 5.9736 0.107 Volume (10^10 km^3) 16.318 108.321 0.151 Equatorial radius (km) 3397 6378.1 0.533 Polar radius (km) 3375 6356.8 0.531 Volumetric mean radius (km) 3390 6371.0 0.532 Core radius (km) 1700 3485 0.488 Ellipticity (Flattening) 0.00648 0.00335 1.93 Mean density (kg/m^3) 3933 5515 0.713 Surface gravity (m/s^2) 3.71 9.80 0.379 Surface acceleration (m/s^2) 3.69 9.78 0.377 Escape velocity (km/s) 5.03 11.19 0.450 GM (x 10^6 km^3/s^2) 0.04283 0.3986 0.107 Bond albedo 0.250 0.306 0.817 Visual geometric albedo 0.150 0.367 0.409 Visual magnitude V(1,0) -1.52 -3.86 - Solar irradiance (W/m^2) 589.2 1367.6 0.431 Black-body temperature (K) 210.1 254.3 0.826 Topographic range (km) 30 20 1.500 Moment of inertia (I/MR^2) 0.366 0.3308 1.106 J[2] (x 10^-6) 1960.45 1082.63 1.811 Number of natural satellites 2 1 Planetary ring system No No _________________________________________________________________ Orbital parameters Mars Earth Ratio (Mars/Earth) Semimajor axis (10^6 km) 227.92 149.60 1.524 Sidereal orbit period (days) 686.980 365.256 1.881 Tropical orbit period (days) 686.973 365.242 1.881 Perihelion (10^6 km) 206.62 147.09 1.405 Aphelion (10^6 km) 249.23 152.10 1.639 Synodic period (days) 779.94 - - Mean orbital velocity (km/s) 24.13 29.78 0.810 Max. orbital velocity (km/s) 26.50 30.29 0.875 Min. orbital velocity (km/s) 21.97 29.29 0.750 Orbit inclination (deg) 1.850 0.000 - Orbit eccentricity 0.0935 0.0167 5.599 Sidereal rotation period (hrs) 24.6229 23.9345 1.029 Length of day (hrs) 24.6597 24.0000 1.027 Obliquity to orbit (deg) 25.19 23.45 1.074 _________________________________________________________________ Mars Observational Parameters Discoverer: Unknown Discovery Date: Prehistoric Distance from Earth Minimum (10^6 km) 55.7 Maximum (10^6 km) 401.3 Apparent diameter from Earth Maximum (seconds of arc) 25.1 Minimum (seconds of arc) 3.5 Mean values at opposition from Earth Distance from Earth (10^6 km) 78.39 Apparent diameter (seconds of arc) 17.9 Apparent visual magnitude -2.0 Maximum apparent visual magnitude -2.91 Mars Mean Orbital Elements (J2000) Semimajor axis (AU) 1.52366231 Orbital eccentricity 0.09341233 Orbital inclination (deg) 1.85061 Longitude of ascending node (deg) 49.57854 Longitude of perihelion (deg) 336.04084 Mean Longitude (deg) 355.45332 _________________________________________________________________ North Pole of Rotation Right Ascension: 317.681 - 0.108T Declination : 52.886 - 0.061T Reference Date : 12:00 UT 1 Jan 2000 (JD 2451545.0) T = Julian centuries from reference date _________________________________________________________________ Martian Atmosphere Surface pressure: 6.36 mb at mean radius (variable from 4.0 to 8.7 mb dependin g on season) [6.9 mb to 9 mb (Viking 1 Lander site)] Surface density: ~0.020 kg/m^3 Scale height: 11.1 km Total mass of atmosphere: ~2.5 x 10^16 kg Average temperature: ~210 K (-63 C) Diurnal temperature range: 184 K to 242 K (-89 to -31 C) (Viking 1 Lander site) Wind speeds: 2-7 m/s (summer), 5-10 m/s (fall), 17-30 m/s (dust storm) (Viking Lander sites) Mean molecular weight: 43.34 g/mole Atmospheric composition (by volume): Major : Carbon Dioxide (CO[2]) - 95.32% ; Nitrogen (N[2]) - 2.7% Argon (Ar) - 1.6%; Oxygen (O[2]) - 0.13%; Carbon Monoxide (CO) - 0.08% Minor (ppm): Water (H[2]O) - 210; Nitrogen Oxide (NO) - 100; Neon (Ne) - 2. 5; Hydrogen-Deuterium-Oxygen (HDO) - 0.85; Krypton (Kr) - 0.3; Xenon (Xe) - 0.08 _________________________________________________________________ Satellites of Mars Phobos Deimos Semi-major axis* (km) 9378 23459 Sidereal orbit period (days) 0.31891 1.26244 Sidereal rotation period (days) 0.31891 1.26244 Orbital inclination (deg) 1.08 1.79 Orbital eccentricity 0.0151 0.0005 Major axis radius (km) 13.4 7.5 Median axis radius (km) 11.2 6.1 Minor axis radius (km) 9.2 5.2 Mass (10^15 kg) 10.6 2.4 Mean density (kg/m^3) 1900 1750 Geometric albedo 0.07 0.08 Visual magnitude V(1,0) +11.8 +12.89 Apparent visual magnitude (V[0]) 11.3 12.40 *Mean orbital distance from the center of Mars. _________________________________________________________________ If no sub- or superscripts appear on this page - for example, if the "Mass" is given in units of "(1024 kg)" - you may want to check the [2]notes on the sub- and superscripts. [3]bullet Notes on the factsheets - definitions of parameters, units, notes on sub- and superscripts, etc. [4]bullet Planetary Fact Table - metric units [5]bullet Planetary Fact Table - U.S. units [6]bullet Planetary Fact Table - Earth ratio _________________________________________________________________ [7]bullet Mars Home Page [8]bullet Directory to other Planetary Fact Sheets [9]bullet NSSDC Planetary Home Page _________________________________________________________________ [NASA Logo] Author/Curator: Dr. David R. Williams, [10]dwilliam at nssdc.gsfc.nasa.gov NSSDC, Mail Code 633 NASA Goddard Space Flight Center Greenbelt, MD 20771 +1-301-286-1258 _________________________________________________________________ NASA Official: Ed Grayzeck, edwin.j.grayzeck at nasa.gov Last Updated: 27 October 2003, DRW References 1. http://nssdc.gsfc.nasa.gov/image/planetary/mars/marsglobe1.jpg 2. http://nssdc.gsfc.nasa.gov/planetary/factsheet/fact_notes.html 3. http://nssdc.gsfc.nasa.gov/planetary/factsheet/fact_notes.html 4. http://nssdc.gsfc.nasa.gov/planetary/factsheet/index.html 5. http://nssdc.gsfc.nasa.gov/planetary/factsheet/planet_table_british.html 6. http://nssdc.gsfc.nasa.gov/planetary/factsheet/planet_table_ratio.html 7. http://nssdc.gsfc.nasa.gov/planetary/planets/marspage.html 8. http://nssdc.gsfc.nasa.gov/planetary/planetfact.html 9. http://nssdc.gsfc.nasa.gov/planetary/planetary_home.html 10. mailto:dwilliam at nssdc.gsfc.nasa.gov