“ Universe, Earth, Oceans and Atmosphere”

Get ready to have your mind blow n!

Quick Quiestion#1 How do you think the universe was created? http://www.teachersdomain.org/asset/ess05_vid_microwave/

Quick Quiestion#3 How Big is the universe? http://scaleofuniverse.com/

Quick Quiestion#2 How can we tell how far away stars are, or what they are made of? http://www.teachersdomain.org/asset/phy03_vid_hubble2/

I. The Origin of the Universe

A. The Big Bang Theory -

The theory that the universe began as a point and has

been expanding ever since.

• Our universe is thought to have begun

as an infinitesimally small, infinitely hot,

infinitely dense, something called a

singularity (which scientist don’t fully

understand! Thought to be the core of

a black whole)

• The tiny, dense sphere expanded

and cooled , forming a gigantic

expanding cloud that moved and

condensed and formed billions of

galaxies

I. The Origin of the Universe

• A few minutes after the Big Bang the first atomic nuclei

formed

• Thousands of years later “our” elements formed

• The first element produced was hydrogen/helium/lithium

• These and other elements in clouds formed gravity, stars,

and galaxies

• The galaxies continue to move outward today

Quick Quiestion#4 Explain in your own words how the universe was created.

II. The Origin of the Solar System

A. The “ Protoplanet Hypothesis”

• 5 billion years ago, a great cloud of gas and dust rotated in

space

• Most of the cloud’ s material gathered in the center, causing it

to shrink and rotate faster into a d isk shape

• The compression made the interior so hot that hydrogen

fusion began and the sun was born

• Masses surrounding the sun separated into rings and collected

to become planets

A. Earth

• was created when from mass surrounding the sun

• Initially one, hot sphere, the interior grew hotter and melted to

form layers of the earth and magnetic fields were formed

B. Age of the Earth

• Earth is estimated to be 4.6 billion years old!

C. Evidence Supporting Age of Earth

• Oldest rocks on Earth are dated 3.96-3.8 billion years old

• Evidence of 4.1-4.2 billion year old crust in Australia

• Moon rocks found to be approx. 4.6 billion years old

III. The Origin of the Earth

D. Conditions on Early Earth

• The early Earth was an uninhabitable, hot ball of molten lava

with a uniform mix of minerals and elements

• Over time, the magma d ifferentiated :

heavy elements sank toward the center (iron)

lighter elements accumulated toward the top (silica)

• 3 d istinct layers formed: hot rad ioactive core, molten mantle and a

thin, brittle crust

Quick Quiestion#5 Draw a visual that shows the layers of the earth.

Quick Quiestion#6 What do you think came first? Oceans or continents?

A. Formation of Crust

• Geologists hypothesize that Earth’ s crust formed as a result of

the cooling of the upper mantle

• Approximately 2 billion years ago, small pieces of continental

crust collided and fused together forming “ supercontinents”

• Today, slabs of crust move, collide and subduct due to the

cycling mantle below, yield ing the current position of the

continents

IV. The Origin of Continents

A. Possible Sources of Water

• Outgassing of water vapor from volcanoes condensed to form

liquid water

• Ice comets landed and melted to form water

V. The Origin of the Oceans

Quick Quiestion#7 How was water created?

A. Earth’s Early Atmosphere

• Contained mostly hydrogen (H), helium (He), methane (CH4) and

ammonia (NH3)

• Outgassing from volcanoes produced water vapor (H2O),

carbon dioxide (CO2), nitrogen (N) and carbon monoxide (CO)

• Earth’s early atmosphere did NOT contain oxygen (02)!

VI. The Origin of the Atmosphere

B. Oxygen in the Atmosphere

• Large mounds of billions of cyanobacteria called stromatolites

dominated the shallow oceans of early Earth

• Through photosynthesis, these bacteria produced enough

oxygen to change the composition of Earth’ s early atmosphere

• Iron oxides in red sed imentary rocks ind icate oxygen was

plentifu l in Earth’ s atmosphere 1.8 billion years ago

• These rocks are referred to as “ red beds”

2.1 billion year old Neguanee Formation, Michigan

Quick Quiestion#8 What do you think the significance of oxygen formation was?

C. Significance of Oxygen in the Atmosphere

• Respiration for animals

• Forms ozone (O3) gas that protects against UV radiation from the

Sun