The Big Bang Theory
A popular theory, the Big Bang Theory explains that around 13.7 bya the universe and space expanded, creating our solar system.
The Atmosphere The Ozone Layer
Earth's atmosphere 4.5bya was mainly composed of volcanic gasses such as: methane, carbon dioxide, ammonia, and no oxygen.
Cenozoic: The era we are currently living in, beginning 65 mya to today, we humans originate in this era.
The Geologic Timescale
Precambrian: The longest era, it is around 87% of Earth's history
Earth's history is divided into four, categorized sections or eras. They are organized by the organisms that dominated that era
Paleozoic: Referred to as the "Cambrian Explosion" it had a sudden increase in the diversity of living organisms, it lasted 544 to 244 mya.
Mesozoic: Lasted 244 to 65 mya, dinosaurs ruled the era until a mass extinction involving an asteroid occurred.
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