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!

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

12 billion years: Big Bang Theory The Big Bang was an explosion of matter that created the universe http://www.aisee.com/anim/ bigbang.htm

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! http://www.youtube.com/watch?v=FhfnqboacV0http://upload.wikimedia.org/wikipedia/commons/e/e4/Redshift_blueshift.svg

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

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

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

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)

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

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

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

250 million years: Pangaea formed All continents formed one SUPERcontinent

Evolution of the modern-day earth http://www.wwnorton.com/colleg e/geo/egeo/flash/2_1.swf

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

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)

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

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

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!