the universe planets planets moons moons stars stars solar systems solar systems galaxies galaxies...
TRANSCRIPT
The Universe
planets moons stars solar systems galaxies nebulae empty space more?
What’s in it?
What’s wrong with this model of the universe?
It is not to scale.
Interstellar cloud of dust and gassesBirthplace of stars
Interstellar cloud of dust and gassesBirthplace of stars
Nebulae
Galaxies
collection of stars, gas & dust held together by gravity
millions of galaxies are known to existgalaxies can contain from hundreds of
thousands to one trillion stars3 major types
● Spiral galaxies ● spiral arms made of stars ● barred spiral - has two or more long
arms extending away from the central “bar” cluster of stars
● Elliptical galaxies ● no spiral arms and no flattened disk
(think football)● Irregular galaxies
● have no regular shape
Galaxies: The Three Types
Milky Way
● Spiral galaxy (Barred-Spiral)● 100,000 light-years in diameter. ● contains about 200 billion stars● Home to Our Sun● the Sun and Earth are located 2/3 away from
center in one of the outer spiral arms● Sun orbits central Milky Way at about 235
km/s around the center of the galaxy
You are here!
Andromeda Galaxynearest galaxy neighbor
about 2.5 million light years away120,000 light years wide
A spiral galaxyThe largest galaxy in our local
group of galaxies
So Where Did It All Come From?
Scientifically believed origins:1. Big Bang
2. Oscillating Universe
3. Geocentric Model
4. Heliocentric Model
Big Bang
The universe was created from one, instantaneous, large explosion outwardmost widely scientific accepted
theory of the origin of the universe
Oscillating Universe
states that the universe grows outward until gravity pulls it back to the center and then expands outward over and over again
Geocentric Model
states all celestial bodies orbit the Earth
Heliocentric Model
states all objects in our solar system circle the Sun.