Past Mars Exploration
Telescopes to Pathfinder
The Beginnings
• Tycho Brahe studies Mars’ motion to
support Copernican view of the Solar
Sytem
• Kepler used this to lay the foundations for
his three laws of motion
• Galileo first to observe Mars with a
telescope in 1609
Canals on Mars?
• Schiaparelli observes Mars in 1877 and
sees “canali”
• This inspires many, including Percival
Lowell to observe Mars.
A Reality Check
• Mariner 4 did the first fly by in 1965 and
sent back pictures and data, including the
following:
Then On to Viking
• Two orbiters and landers arrive in Martian
Orbit in 1976
Mars Global Surveyor
• Arrives in orbit in 1996 and aerobrakes
into a circular orbit over a period of two
years
Pathfinder 1997
Spirit and Opportunity
Mars Statistics
• Mass (kg) 6.421e+23 Mass (Earth = 1) 1.0745e-01
• Equatorial radius (km) 3,397.2 Equatorial radius (Earth = 1)
5.3264e-01
• Mean density (gm/cm^3) 3.94
• Mean distance from the Sun (km) 227,940,000
• Mean distance from the Sun (Earth = 1)1.5237
• Rotational period (hours) 24.6229
• Rotational period (days) 1.025957
• Orbital period (days) 686.98
• Mean orbital velocity (km/sec) 24.13
• Orbital eccentricity0.0934
• Tilt of axis (degrees) 25.19 Orbital inclination (degrees) 1.850
• Equatorial surface gravity (m/sec^2) 3.72
• Equatorial escape velocity (km/sec) 5.02
• Visual geometric albedo0.15
• Magnitude (Vo)-2.01
Minimum surface temperature-140°C
Mean surface temperature-63°C
Maximum surface temperature 20°C
Atmospheric pressure (bars) 0.007
Atmospheric composition
Carbon Dioxide (C02)
Nitrogen (N2)
95.3200%
2.7000%
Argon (Ar)
Oxygen (O2)
Carbon Monoxide (CO)
1.6000%
0.1300%
0.0700%
Water (H2O)
0.0300%