Earths Place In Space● Origin Of The Universe – Big Bang Theory – How our solar system formed● Earths Early Atmosphere● Evolution
Origin Of The Universe● Big Bang Theory – Scientists believe that there was a giant explosion around 12-14 billion years ago. – Atomic particles from the explosion later formed galaxies, stars, and planets.
Supernova– 7 Billion years ago, a supernova occurred from one of the first generations of giant stars exploding.– A supernova occurs at the end of a stars life, releasing huge amounts of energy.
Solar Nebula– The energy released from the first generation of stars exploding, produced a solar nebula.– A solar nebula is thought to be a spinning cloud of dust and gas.
Solar Nebula● Gravity caused the spinning could of dust and gas to collapse and condense forming our Sun in the center.● The other lumps of matter that formed from the contracting dust and gas became the planets.
Earths Early Atmosphere● 4.6 billion years ago, Earth was nothing more than a molten ball of rock surrounded by an atmosphere of hydrogen and helium.● As the Earth cooled enough to form a solid crust, it was covered with active volcanoes.
Earths Early Atmosphere● These volcanoes spewed out gasses, like water vapor, carbon dioxide, and ammonia forming Earths early atmosphere.
Earths Early Atmosphere● Very little oxygen● No ozone layer – Early life could only survive in the ocean (UV radiation)● Early organisms used energy from the Sun for photosynthesis. – Conversion of the suns energy into chemical energy by living organisms. – Oxygen was released as a byproduct.
Earths Early Atmosphere● As oxygen increased, the ozone layer was formed protecting Earth from harmful radiation.● This allowed for plant life to evolve and made it possible for the evolution of animal life on land.