Mean Distance from Sun: 227.9 million kilometers
Inclination of Orbit to Ecliptic: 1.9 degrees
Eccentricity of Orbit: 0.093
Period of Revolution (Year): 687 days
Rotation Period (Day): 24 hours, 37 minutes
Inclination of Axis: 25 degrees and 12 minutes
Equatorial Diameter: 6,794 kilometers
Planet Volume: 1.63 x 10^22 cubic meters (m^3)
Planet Mean Density: 3.93 grams per cubic centimeter (g cm^-3)
Mean Surface Gravity: 3.72 meters per second
Gravity as Compared to Earth: 0.38 (where Earth gravity = 1)
Atmosphere (Main Components): Carbon Dioxide: 95.3%
Nitrogen: 2.7%
Argon: 1.6%
Oxygen: 0.1%
Average Atmospheric Pressure: 6.5 millibars (Earth is approx 1 bar)
Two Moons: Phobos (13.3 by 11.1 by 9.3 km elliptical moon)
Deimos (7.6 by 6.2 by 5.4 km elliptical moon)
Sources:
Hugh H. Kieffer, Bruce M. Jakosky, and Conway W. Snyder, "The Planet Mars: From Antiquity to the Present," in H.H. Kieffer et al., Mars, pp. 1 - 33, University of Arizona Press, Tucson, 1992.
"Charting the Planets," NASA Educational Brief EB-112, May 1993.