MARS

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

Facts: Temp: -195 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

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

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

SURFACE FEATURES Plains Canyons Volcanoes Valleys and gullies Polar Ice

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

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

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

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

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

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)

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

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

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)

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

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

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

http://www.pbs.org/wgbh/nova/mars/launchland.html