1. MARS

2. MARS Named after Roman god of War Greek name was Ares
Known as the Red Planet
Red color is due to high iron (Fe) content and similar to oxidation on Earth

3. Facts:
Temp: F to 70 F
Distance from Sun: 141,620,000 miles (1.5 times farther from Sun than Earth)
Diameter: 4,212 miles (1/2 of Earth)
Revolution: 687 days
Rotation: 24 hours 39 minutes 35 seconds

4. More Facts Tilt of axis: 25.19 degrees
Distance from Earth: Close: 33,900,000 miles
Far: 249,000,000 miles
Gravity: 38 % of the Earth’s
About 1/10 as massive as Earth

5. FEATURES Similar crust and mantle to Earth
Composed mainly of peridotite (olivine)
Core is Fe, Ni, and S
Most likely a solid core
No significant magnetic field
Rocks studied show magnetic properties so Mars probably had a molten core in past

6. SURFACE FEATURES Plains Canyons Volcanoes Valleys and gullies
Polar Ice

7. PLAINS Found mostly in Northern Hemisphere
Flattest and smoothest in Solar System
Possibly from settling sediments
Few craters but immense
Largest is 1400 miles in diameter and 5.5 miles deep

8. CANYONS Along equator – Valles Marineris
Runs east-west for 2500 miles (Australia)
Formed by rifting
60 miles wide, 5 to 6 miles deep
Erosion marks indicate to presence of water

9. VOLCANOES Largest in the solar system
Olympus Mons – 17 miles high 370 miles around
Similar to Hawaii in shape
May still be slightly active

10. VALLEYS Known as outflow channels 60 miles wide, 1200 miles long
Appeared to carved during floods
Other areas have networks like river systems on Earth
Suggest that the planet may have had water as a liquid in ancient time

11. POLAR ICE Caps of water ice that remain frozen year round
Several miles thick
In winter, additional caps form or spread from layers of frost (CO2 or dry ice)
Extend down to halfway to equator

12. ATMOSPHERE .13 % oxygen (Earth = 21 %) CO2 95.3 %
Pressure = 0.1 lbs/inch2
Clouds form as well as fog and frost from frozen CO2
Winds are 55 m.p.h. (mild due to thin atmosphere)

13. DUST STORMS Can last for months Lift dust high in atmosphere
Cover an area 200 to 1000 miles, even the entire planet
More common when planet is closer to sun
Dust absorbs sunlight, warming the air, lifting more dust

14. SATELITES 2 moons Phobos – 17 mile diameter Deimos – 9 mile diameter
Many craters on them despite size

15. EXPLORATION Earth BASED
Polar caps discovered by telescope in 1800’s
Winds as light and dark material was seen moving on surface
“Canals” found suspected life on Mars (Lowell)

16. SPACECRAFT Mariner 4 in 1964 Mariners 6 and 7 in 1969
Pictures proved to be a barren landscape
No water
No life
Saw only cratered region

17. SPACECRAFT 1971 Mariner 9 went into orbit mapped 80% of surface
Discovered volcanoes, canyons, and dry riverbeds
Series of probes/orbiters through the the 90’s and early 2000’s provided more information and tested new landing system

18. MARS ROVERS Spirit and Opportunity landed in 2004
Transmitted detailed photographs and tested soil
Found strong evidence for water from sulfates, salts and sediments