The Birth Of The Earth

Question 1

Bombardment Era

Answer 1

• The 1st half BY of Earth’s existence

* The surface of the Earth was repeatedly pulverized by asteroids and meteors

Question 2

The Formation of the Moon

Answer 2

• A planet named, Thea, collided with Earth (about the size of Mars)
• 50 MY after the creation of the Earth
• The collision caused large amounts of debris to leave the Earth’s atmosphere
• The debris orbited the Earth and eventually condensed to form the moon

Question 3

What are the 4 Spheres of Earth

Answer 3

1. Atmosphere
2. Hydrosphere
3. Geosphere
4. Biosphere

Question 4

Describe the creation of Today’s Atmosphere

Answer 4

• 1st: Thin atmosphere, that Earth’s gravity couldn’t hold so released into space
• 2nd: Volcanoes began to create a thicker atmosphere (made of a variety of acidic gases)
• Today’s: 78% Nitrogen, 21% Oxygen and 1% Trace Gases

Question 5

Hydrosphere

Answer 5

• Took 100s MYs to get water
• Covers 70% of Earth
• Most abundant element is oxygen and hydrogen

Question 6

Why are Oceans salty?

Answer 6

The rain breaks down the rocks and carries the salt to streams and rivers and then to ocean

Question 7

Geosphere

Answer 7

The solid earth that includes continental and oceanic crust as well as the various layers of Earth’s interior

Question 8

Biosphere

Answer 8

The total of all the ecosystems of living things on Earth

Question 9

Name the Layers of the Earth

Answer 9

• Crust
• Mantile
• Outer Core
• Inner Core

Question 10

Crust

Answer 10

• 1% of Earth
• Cool
• Made up of solid rock
• Most abundant element is Silicon and Oxygen

Question 11

How and When did the Earth start forming?

Answer 11

• Started forming about 4.5 Billion YA

• Made from dust and gas leftover from the Sun
• 10-20 MY to form the Earth