1. History of the Earth
Order these vocabulary words from smallest to largest : universe, solar system, planet, galaxy
How are the geocentric and heliocentric models similar? How are they different?
Explain why this is incorrect: “If the Earth’s orbit got smaller, the length of the Earth’s year would increase.”
Write in complete sentences!
Don’t talk during the Catalyst!

2. Objectives
By the end of today, all SWBAT…
Describe the Big Bang Theory
Describe 7 important events in the history of the earth

3. 12 billion years: Big Bang Theory
The Big Bang was an explosion of matter that created the universe
bigbang.htm

4. Evidence of Big Bang Theory
The redshift
When something that emits light moves farther away, the light looks more red
Light from faraway galaxies looks red…
Which means the universe is still expanding today!

5. http://www.lon- capa.org/~mmp/ap plist/doppler/d.htm
Redshift!
capa.org/~mmp/ap plist/doppler/d.htm

6. Formation of earth Cloud of dust formed called nebula
Nebula forms disc with a ball surrounded by rings
Central ball forms sun and the rings form the planets of the solar system

7. 4 billion years: Earth’s atmosphere
The Earth’s atmosphere was formed by volcanoes that released gas as they erupted
Gases:
Nitrogen (N2)
Water (H2O)
CO2
SO2
NO oxygen here

8. 3 billion years ago: Continents formed
The lithosphere cracked into pieces (plates) as the Earth cooled.
The plates collided to create continents
Lithosphere = outer solid part of the Earth (crust and upper mantle)

9. 2.5 billion years: Oceans formed
Water collected as oceans when Earth cooled

10. 2 billion years ago: First plants
Plants added oxygen to the atmosphere (through photosynthesis)

11. 340 million years ago: First Reptiles
Reptiles were the first animals to live on land

12. 250 million years: Pangaea formed
All continents formed one SUPERcontinent

13. Evolution of the modern-day earth
e/geo/egeo/flash/2_1.swf

14. 500,000 years: First Homo sapiens
Homo sapiens: modern-day humans

15. If Earth’s history were a pie graph…
If we were to think of the universe’s creation as in a 24 hour period, humans showed up in the last minute of the day (11:59)

16. Activity: Cat in the Hat
With a partner, quiz each other by pulling questions out of the “hat”

17. Earth’s History Timeline
As a class we will put together a timeline of the history of earth.
Each group will be responsible for creating a poster of ONE EVENT in this history
Each poster must have:
Title
3 facts about the event
Picture
Include WHEN the event occurred

18. Exit questions What happened in the Big Bang?
Place these events in the correct order (from oldest to most recent)
First animals
Atmosphere formed
Continents formed
First plants
Write in complete sentences!
Don’t talk during the Exit Question!