Download The Inner Planets

The Inner Planets
Mercury
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Small
Weak gravitational force
No atmosphere
Many craters
• Caloris Basin - one giant crater (1000 miles in
diameter)
• Many cliffs and peaks evidence of tectonic
activity
• Mean surface temp  442.5 K, ranges from
100 K to 700 K
http://solarsystem.nasa.gov/multimedia/videos/
Keplers_Laws_fullscreen.mov
Venus
Earth’s sister planet
• Covered with an opaque layer of highly
reflective clouds of sulfuric acid
• Surface temperatures high enough to melt
lead.
After the Moon, it is the brightest
natural object in the night sky
• Orbits every 224.7 Earth days
• Rotation is slow and retrograde, 243-day
period
• Time from one sunrise to the next is 117 Earth
days
http://en.wikipedia.org/wiki/File:VenusAnimatio
n.ogg
• Radius is 95% of Earth's, and the density
similar to Earth's, 80%
• Liquid metal core similar to the Earth's
Atmosphere
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Thick, high pressure (90 atm)
Density 50 times greater than on Earth!
Made of CO2, N, with sulfuric acid clouds
Strong greenhouse effect
Surface
• 450°C (850°F) hot!! everywhere, always,
including night time
• Dry, dusty rocks, no water
• May have had water in the past
• Orange light, (atmosphere reflects mostly blue
light)
Phases of Venus
http://www.youtube.com/watch?v=ukPGqz4e_T
Y&feature=related
Mars
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most ``earthlike''
1/2 size of Earth
24h 37m day
thin atmosphere of 95% CO2
much colder than Earth -- 187o K to 244o K (123o F to -20o F )
• atmospheric pressure 0.7% of Earth's
(equivalent to 100,000 ft altitude on Earth)
• tilted 25o ---> seasons
• dust storms originally thought to be bands of
vegetation ad irrigation canals built by
Martians!
• http://www.disclose.tv/action/viewvideo/160
67/Orson_Welles__War_Of_The_Worlds_Pt_2
_7/
• clouds, sediment layers, canyons, landslides,
sand dunes, enormous young volcanos as tall
as 78,000 ft (flyby 1 and flyby 2)
• dry riverbeds (in older regions), evidence that
liquid water once flowed
• no water in liquid state now, all water frozen
in ice caps/permafrost
• The "Red Planet”  iron oxide
• Two moons, Phobos
Deimos
Surface features similar to Earth and
the Moon
Atmosphere
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Carbon dioxide 95.32%
Nitrogen 2.7%
Argon 1.6%
Oxygen 0.13%
Ice caps
First fly-by
• Mariner 3 (1965)
• http://www.hulu.com/watch/63307/cosmosblues-for-a-red-planet