1. History of Life But 1 st an Intro Video

3. Timeline Big Bang: ~13.75 bya (billion yr ago) – or 13.75 Ga Giga = Ga = 10^9 – or 433.6 x 10^15 seconds (SI base unit) Milky Way Galaxy: ~13.2 bya Sun: ~4.57 bya Earth: ~4.54 bya Moon: ~4.53 bya, ~30–50 mya after the Solar System

4. Formation of Galaxies ~ 1 billion years after the Big Bang... Some clumps of matter dispersed by their internal motions, others grew by attracting other nearby matter. Surviving matter clumps became the beginnings of today's galaxies. When a clump becomes massive enough, it starts to collapse under its own gravity & becomes a protogalaxy.

5. Galaxies & Within (intragalaxies) large groupings of stars, dust, and gas held together by gravity contain all the familiars: billions of stars, some with planets, moons, comets, asteroids. & the less familiar: nebulae, neutron stars, black holes, and dark matter

6. The Milky Way: Our galaxy 1 ly = ~10 trillion km (10^16 m) = ~ 6 trillion miles

7. Within the early Milky Way: Nebula: giant clouds of gas, dust, & the birthplace of stars

8. Crab Nebula in visual spectrum from Hubble telescope

9. Nebular Theory: The theory that explains the formation of Earth and it’s solar system.

10. The Earth, like all the other planets, formed out of the disk of gas and rocks that orbited the sun.

12. If the Earth was made out of a bunch of chunks of rock that collided and stuck together... what would it be like inside?

14. 4.54 bya, when Earth had reached it’s final size, it was a hot and lifeless planet.

15. Formation of Earth's Moon

17. continuous bombardment by meteorites, and intense volcanism 4.1 bya - 3.8 bya: Late Heavy Bombardment at the end of the Hadean Eon

18. Achaean Eon Earth has significantly cooled, no stable atm, no O 2, no O 3 LIFE?

19. End of Part 1