You know the drill, Page 608: The Atmosphere

Venus: Thick atmosphere Daytime Temp = 900°F Nighttime Temp = 820°F Mars: Almost no atmosphere Daytime Temp = 50°F Nighttime Temp = -94°F Mercury: No atmosphere Daytime Temp = 800°F Nighttime Temp = -280°F Earth: Medium atmosphere Daytime Temp = 74°F Nighttime Temp = 48°F

Venus: Thick atmosphere Daytime Temp = 900°F Nighttime Temp = 820°F Mars: Almost no atmosphere Daytime Temp = 50°F Nighttime Temp = -94°F Mercury: No atmosphere Daytime Temp = 800°F Nighttime Temp = -280°F Earth: Medium atmosphere Daytime Temp = 74°F Nighttime Temp = 48°F

Benefits from Our Atmosphere Keeps planet warm… but not too warm Prevents heat from escaping at night Allows for water cycle Allows for breathing (plants and animals) Blocks some incoming radiation Perfect for flying kites

The Atmosphere Is Made of… Argon (Ar) – 1% Oxygen (O2) – 21% Other Gases: Carbon Dioxide (CO2) – 0.04% Water Vapor (H2O) – 0 to 1% Neon (Ne) – 0.002% Miscellaneous – <0.001% Nitrogen (N2) – 78%

Exosphere Thermosphere Mesosphere Stratosphere Troposphere

Exosphere (basically outer space) Thermosphere (the last molecules) Mesosphere (where astronauts chill) Stratosphere (above the weather) Troposphere (where we live)

Exosphere (basically outer space) 300 miles Thermosphere (the last molecules) 50 miles Mesosphere (where astronauts chill) 30 miles Ozone Layer (O3) Stratosphere (above the weather) 7 miles Troposphere (where we live)

What Happens When It’s Heated?

COOL HOT

Uneven heating creates natural convection currents (wind), with air typically moving from cold to hot at ground-level. COOL HOT