Download The Earth`s Formation

The Earth’s Formation
Physical and chemical processes change our planet everyday
Earth as we know it is the result of events that happened ______________________
The most widely accepted model of the formation of the solar system is called the
____________________
According to scientists, the Earth and our solar system formed about
_______________________
The Nebular Hypothesis states _______________________________________________ called a
nebula
The cloud (nebula) was over 10 billion kilometers in diameter
Originally a large ___________________________________ became unstable
The most dense part of the cloud started to collapse under the __________________
Gravity pulled the dust and gas toward the center of the cloud, causing the cloud to take on a
spherical shape.
This cloud started rotating, and the dust particles combined to form
______________________
The planetesimals combined to form _________________________________________________
The planetesimals ___________________________, sometimes colliding with other objects in
space.
Eventually these objects develop into planets and moons.
Earth’s Size and Shape
•
Earth is an __________________________________________
•
Total surface area – ______________________________
•
149 million square kilometers above sea level (dry land)
•
______________________________________________
Earth’s Interior
The Earth is like an onion. Its made of layers
The Inner Core
•
Composed of ___________________________________
•
6371 km from the surface
•
Temperature – ________________________________
The Outer Core
•
Composed of _________________________________
•
5150 km from the surface
•
Temperature – ___________________________________
The Mantle
• Composed mostly of _______________________________________
• _________________________________________
• 2890 km from the surface
• 1500 – 3200 degrees Kelvin
The material in the mantle is known as ‘magma’
Magma is _____________________________________________________________
The Crust
• ________________________________________________________________
• 0-65 kilometers from the surface
The crust is divided into 2 layers classified by the physical properties
Asthenosphere – ___________________________________
__________________________ – composed of the upper mantle and crust
In summary, the Earth was formed about 4.6 billion years ago from a whirling cloud of dust and
gas called a nebula.
It developed layers, like a jawbreaker, as it cooled and dense material sank to the center.