Download The Inner Planets

The Inner Planets
Read pages 38-45 and fill in as much
as you can on the table
Mercury-Roman Messenger God
• Composition: Rocks/iron rich core
• Size: Smallest planet in the solar system, about the size of
our moon
• Atmosphere: Very little to none; not enough gravity and too
hot
• Hydrosphere: None
• Geosphere: Lots of craters, but nothing to wear them
down; no plate tectonics/volcanoes
• Temperature: Closest to the sun, temperature ranges from
430 C to -170 C
• Fun Fact: Orbits in less than one Earth year; Very long days
(58 earth days long)
Venus-Roman Goddess of Love
• Composition: Rocks/iron rich core
• Size: Nearly the same size as Earth
• Atmosphere: Very thick clouds cover the entire planet,
air is mostly carbon dioxide and sulfur; hottest planet
due to greenhouse effect
• Hydrosphere: 0.002% water vapor
• Geosphere: Heavy volcanic activity-more volcanoes
then anywhere else, no plate tectonics
• Temperature: 465 C (hot enough to melt lead)
• Fun Fact: Rotates backwards (clockwise); it’s day is
longer than it’s year
Earth
• Composition: Rocks, iron core
• Size: Radius is 3,959 miles (6,371 km)
• Atmosphere: N and O mostly; offers UV
protection from ozone layer
• Hydrosphere: Water present in all three forms
• Geosphere: Only planet with plate tectonics
• Temperature: Average temperature is 14 C
• Fun Fact: It’s not a perfect sphere!
Mars
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Composition: Rock, iron rich core
Size: About the size of our core
Atmosphere: Thin, mostly carbon dioxide
Hydrosphere: Snows on Mars (dry ice and water ice); has
frozen water at the poles; thought to have water in the past
• Geosphere: Largest volcano in the solar system (Olympus
Mons); has canyons but no evidence of plate tectonics
• Temperature: -140 C to 20 C
• Fun Fact: Largest canyon in the solar system (Valles
Marieneris)
Earth vs. The Inner Planets
• We are the habitable zone
– We call this the Goldilocks zone because it not too hot
or too cold it’s just right
– Allows us to have all three states of water
• We believe that life started in the oceans and
early life started photosynthesis to give us
oxygen, therefore we believe liquid water is
required for life on other planets
• Atmosphere filters out harmful radiation from the
sun, not seen on other planets