1. Chapter 12 Space Exploration

2. Section 12.1 page 428 Explaining the Early Universe GALAXY – collection of stars, planets, gas and dust held together by gravity SOLAR SYSTEM GALAXY – Milky Way UNIVERSE

3. Measuring Distances in Our Universe Distances within our Universe are measured in light years 1 light year = distance light will travel in 1 year = 9.5 trillion km Speed of light = 300, 000 km/s

4. Hubble’s Proposal The Universe is expanding, galaxies are moving away from each other The further away the Galaxy, the faster it is moving The Doppler Effect

5. THEORIES OF THE ORIGIN OF THE UNIVERSE

6. THE BIG BANG THEORY Since there is evidence that our Universe is Expanding, it must have started somewhere! ~13.7 billion years ago there was a massive expansion Very High Temperatures ~ 1 billion °C Very Rapid Expansion Open Universe – one that will Expand forever Theme SongBirth of a Universe T=2:50 Theme SongBirth of a Universe

7. THE OSCILLATING THEORY Closed Universe – one that will Expand so far and then drawn back by gravitational forces, all the matter will meet again in a “Big Crunch” – This theory says the Universe goes through a series of bangs and crunches in an ongoing cycle – Currently still expanding from the most recent explosion

8. THEORIES OF THE ORIGIN OF THE SOLAR SYSTEM

9. STELLAR COLLISION THEORY This Theory says that Our Solar System was created from the spin off of colliding stars!

10. NEBULAR HYPOTHESIS Nebulae(Nebula)-H 2 gas and dust between stars - When pulled together by gravity, stars form if hot enough - A nearby exploding star could have caused a shock wave which started the process -Starts to rotate as it collapses

11. Section 12.2 Galaxies and Stars SPIRALELLIPTICAL Our Milky Way Galaxy, Earth is on a spiral arm, we see the center on it’s side at night Some of the oldest and largest galaxies are elliptical, more then 50% of galaxies are this shape

12. THE EVOLUTION OF STARS DWARF STARS GIANT STARS Small, burn fuel slowly, last a long time (100 billion years) red dwarfs to white dwarfs and burn out Fate of our Sun Large, burn fuel quickly, last a short time RED GIANTS to white dwarf to black dwarf OR SUPER GIANTS supernova to neutron star to black hole

13. The life cycle of Stars

14. BLACK HOLE Sphere of extremely dense material with a gravitational pull so strong not even light can pass out of it! Created when a SUPER GIANT star collapses in on itself Dark Matter Black Hole SciShow

15. Evidence 1.Electromagnetic Radiation detected of matter being pulled into it 2.The effect of it’s gravity on the movement of nearby stars and galaxies 3.Data collected supported by computer generated models

16. QUASAR Region of extremely high energy which develops around a supermassive black hole as matter is attracted into itself Brightest bodies in our Universe Quasar Clip