Chapter 12 Space Exploration Section 12.1 page 428 Explaining the Early Universe GALAXY – collection of stars, planets, gas and dust held together by gravity UNIVERSE GALAXY – Milky Way SOLAR SYSTEM 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 Hubble’s Proposal • The Universe is expanding, galaxies are moving away from each other • The further away the Galaxy, the faster it is moving Evidence – Red Shift Analysis • Based upon Electromagnetic Radiation (waves) • A spectroscope allows astronomers to view patterns of different stars, thus astronomers can identify and determine patterns of stars Red Shift! Spectrum of a non-moving star Spectrum of a star moving Towards Earth (waves contract as the object moves closer) Spectrum of a star moving Away from Earth (waves expand as a distance increases) THEORIES OF THE ORIGIN OF THE UNIVERSE 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 explosion • Very High Temperatures ~ 1 billion °C • Very Rapid Expansion Open Universe – one that will Expand forever Big Bang Timeline 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 THEORIES OF THE ORIGIN OF THE SOLAR SYSTEM STELLAR COLLISION THEORY • This Theory says that Our Solar System was created from the spin off of colliding stars! NEBULAR HYPOTHESIS Nebulae(Nebula)-H2 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 Section 12.2 Galaxies and Stars SPIRAL ELLIPITICAL Our Milky Way Galaxy, Earth is Some of the oldest and largest on a spiral arm, we see the galaxies are elliptical, more center on it’s side at night then 50% of galaxies are this shape THE EVOLUTION OF STARS DWARF STARS GIANT STARS Large, burn fuel quickly, last a short time Small, burn fuel slowly, last a long time (100 billion years) red RED GIANTS to white dwarf to dwarfs to white dwarfs and black dwarf burn out OR SUPER GIANTS supernova to neutron star to black hole 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 QUASAR • Region of extremely high energy which develops around a supermassive black hole as matter is attracted into itself The Future of Space Exploration Pilots Technicians Engineer Careers Related to Space Astronaut Scientist Doctor.