MARS

1.5 AU
Radius = 0.53 R_earth
Mass = M_earth / 9
Gravity = 0.4 G_earth
Density = 4 gm/cc
Period = 1.9 years
Albedo = 16%
other facts

ORBIT

• day = 24.6 hr = Earth's
• tilt 25 deg = Earth's

=> 4 seasons, 6 mos each

• RED planet
• from RUST - iron oxides

=> not differentiated much
• surface area = Earth's land area
 
• huge volcanos
• Why?
  • weaker gravity
  • no continental drift
• Olympus Mons - 15 x 360 mi . . . (perspective)
- 3 times taller than Mt. Everest (29,000 ft = 5.5 mi)
- base as wide as Alabama is N-S
- cliff base 4 miles tall -- like Mt. McKinley (20,000 ft)
• active volcanos?
  - meteor crater counting => "young" (few-100 million yr)
  - 100 million yr / 4.5 billion yr = 2% of age
  - 2 million yr / 4.5 billion yr = 0.05% of age
• huge valley - Valles Marineris
• 3000 mi x 300 mi x 4 mi
• 5-10 x longer, deeper, wider than Grand Canyon
• as long as U.S. is wide
• crack in Tharsis uplift (1/4 all) - not erosion

 
• cratered S. Hem
• Victoria crater
• zoom view of rover at crater edge
• view from rover
lava-filled basins
• shallow - water erosion

 
• RUNNING WATER . . .
. . . NOW! . . . NOW! . . . more NOW . . . more images
. . . water droplets on Phoenix lander?
. . . & in PAST
• sinuous channels
• chaotic collapse - melt, flood
• erosion
• chemistry - Mars Rover gallery -- landing map
• WHERE IS MOST WATER NOW ?
• permafrost
  • frozen seas?
  • glaciers?
• polar caps
• seasonal - summer N gone
• carbon dioxide ice on top
• water ice below
• 1-1.5 miles thick
• enough water to cover surface 60 foot deep
• wind features
• sand dunes - (frosty dunes)
• terracing in polar caps
• streaks
• dust devils - phoenix lander view

INTERIOR

• less dense -- not differentiated much
• smaller core

 

ATMOSPHERE

• thin & freezing
• Composition: CO₂ carbon dioxide
• Surface temperature -200 --> +80 F
• Structure: clouds of water, CO₂ ice
• Weather
• local & global wind storms (70 mi/hr at surface)
• S Hem summer hottest
• Mars closer to Sun
• extra convection
• blowing dust varies look