Formation and Layers of Atmosphere - MRS. CARLYLE'S …
Transcript of Formation and Layers of Atmosphere - MRS. CARLYLE'S …
FORMATION OF THE ATMOSPHERE
Atmosphere -gases that surround the Earth.
Earth’s 1st Atmosphere 4.6 billion years ago
Made of Hydrogen (H) & Helium (He).
Earth’s 1st Atmosphere 4.6 billion year ago
These light gasses (H & He), were heated by solar radiation and escaped the gravitational pull of earth.
The gasses were carried away by the solar wind.
FYI: Venus and Mars also had the same
1st atmosphere of H & He.
Earth’s 2nd atmosphere Volcanic eruptions all over earth produced
water vapor, carbon dioxide, & nitrogen gas.
Earth’s 2nd atmosphere
The only living organisms were bacteria and microorganisms.
100’s of millions of years passed
Earth’s 2nd atmosphere
The earth continued to cool & water vapor formed clouds.
Rain fall formed the oceans. Some astronomers also believe our water
came from comets.
Earth’s third atmosphere (Our Current Atmosphere)
Oxygen appeared when energy from the sun broke the water vapor H2O into H & 0.
Earth’s third atmosphere (Our Current Atmosphere)
However, most of the
oxygen came from photosynthesis, when plants appeared 2-3 billion years ago.
Photosynthesis makes
oxygen by turning H20 and CO2 into organic matter.
As plants became wide spread oxygen became abundant in the atmosphere.
Today our atmosphere is: • 78% Nitrogen (N2) • 20.95% Oxygen (O2) • 0.93% Argon (Ar) • 0.038% Carbon Dioxide (CO2) • trace amounts of Other gases (ex: H2O )
Earth’s third atmosphere (Our Current Atmosphere)
Earth’s Atmospheric Gasses
Layers of the Atmosphere
Key Concepts
Order of the Layers
1. Troposphere 2. Stratosphere 3. Mesosphere 4. Thermosphere
Troposphere The layer of the atmosphere where weather occurs
Stratosphere The layer of the atmosphere that contains ozone
Mesosphere The layer of the atmosphere where most meteoroids burn up
Thermosphere The hottest layer of the atmosphere that’s divided into two parts
Ionosphere Thermosphere layer that bounces radio waves
Exosphere Outermost layer of the thermosphere