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 SOLAR SYSTEM GALAXY – Milky Way UNIVERSE

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 Youtube clipYoutube clip and AgainAgain

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 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

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)-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

Section 12.2 Galaxies and Stars SPIRALELLIPITICAL 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 ellipitical, more then 50% of galaxies are this shape

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

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

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

QUASAR Region of extremely high energy which develops around a supermassive black hole as matter is attracted into itself

The Future of Space Exploration Careers Related to Space Engineer Astronaut DoctorScientistPilotsTechnicians