Earth Science - Unit 9: Earth's Atmosphere. Lesson 1:Evolution of the Atmosphere
The atmosphere has many roles, including:
provides gases for respiration and photosynthesis provides protection from UV radiation and meteorites stabilizes a habitable temperature
The first major source of oxygen gas was _____.
cyanobacteria.
In the paleoatmosphere, the primary gases were _____.
carbon dioxide, nitrogen, and water vapor.
What force keeps our atmosphere from floating out into space?
Gravity.
The earth has fewer meteorite impacts because_____.
Of the earth's atmosphere.
Most life would not be possible without our unique atmosphere.
True.
Which of the following factors caused the early atmosphere to become thicker?
volcanic outgassing and meteorite and comet impacts.