PPT Slide
Life On Earth: Earth’s Early Atmosphere
Whatever life is, on Earth it originated on a planet with very different characteristics than that which Earth has today
Oceans as we know them did not yet exist - they were newly forming….
Surface was constantly bombarded by comets and asteroids..
Atmosphere forms from gases released from Earth’s interior - Contains H2O, H2, CO, CO2, N2, CH4, NH3 and S products
Young Sun bombards Earth with more UV, but less overall energy than now….
Prior to oxygen-producing photosynthesis occurring, Earth’s atmosphere was a reducing (electron-adding) agent, rather than the oxidizing (electron-removing) one….