In November 1996, NASA and the Jet Propulsion Laboratory began America's return to Mars after a 20-year absence by launching the Mars Global Surveyor (MGS) spacecraft. The MGS mission will recover most of the lost objectives of the 1992 Mars Observer mission by delivering a single spacecraft to the red planet for a two-year study of Mars' surface, atmosphere, and gravitational and magnetic fields. Achieving the scientific objectives of the MGS mission will require placing the spacecraft in a low-altitude, near-polar, Sun-synchronous orbit around Mars and returning data over a complete Martian year.
Mass (kg) 6.42 x 10^23
Diameter (km) 6787
Mean density (kg/m^3) 3940
Escape velocity (m/sec) 5000
Average distance from Sun (AU) 1.524
Rotation period (length of day in Earth days) 1.026
Revolution period (length of year in Earth days) 686.98
Obliquity (tilt of axis in degrees) 25
Orbit inclination (degrees) 1.85
Orbit eccentricity (deviation from circular) 0.093
Maximum surface temperature (K) 310
Minimum surface temperature (K) 150
Visual geometric albedo (reflectivity) 0.15
Highest point on surface: Olympus Mons
(about 24 km above surrounding lava plains)
Atmospheric components: 95% carbon dioxide, 3% nitrogen, 1.6% argon
Surface materials: basaltic rock and altered materials
Last Modified: 13 March 2003
Contributors: Andrew Acuņa, David Brain, Monte Kaelberer, Sandy Kopman, Cisco Perin, and Theresa Valentine
Curator: Patricia Lawton, L-3 Communications EER Systems, Inc.
Email: Patricia.Lawton@gsfc.nasa.gov
Responsible NASA Representative: Mario Acuña
Email: Mario.H.Acuna@nasa.gov