Definitions, Explanations and Pictures The Formation, Size, Shape and Layers of the Earth Definitions, Explanations and Pictures

Converge: To come together Condense and Converge Condense: To become more compact Converge: To come together

Steps: Formation of the Solar System 1. Large, cold cloud of dust and gas condenses- typically in a nebula 2. The cloud spins, heating the material and dividing the cloud into a cold disk of rock and ice surrounded by hotter gas

Formation Continued 3. Fusion first occurs in the new star (the Sun) and little planets form 4.Over time, nearly all of the original material becomes a part of the star and its orbiting planets

Formation of the Solar System

Fusion The coming together of certain elements (in the case of the sun; hydrogen) that result in helium and the release of large amounts of energy.

Earth’s Interior The heated materials that formed the Earth sorted out by density Inner core: Composed of solid iron and nickel (solid due to intense pressure) Outer core: Composed of liquid iron and nickel. Mantle: The thickest layer of Earth, composed of iron, silicon, and magnesium. The mantle is a solid that can act like a liquid Crust: Thin, rigid layer of lighter rocks. Includes Earth’s surface

Smooth Oblate Spheroid The Earth has a polar axis that is shorter than the diameter of the equatorial circle, therefore, the Earth bulges at the middle. Even with mountains like Everest, the Earth is relatively very smooth Good models of Earth’s true appearance are billiard balls, marbles, and ping pong balls

Size and Shape of the Earth (do not write) The total surface area of the Earth is about 510 million square kilometers, which is equivalent to about 55 continental United States

Percentages 29% of Earth’s surface is dry land 71% is covered by water The percentage covered by water is slowly increasing as polar ice melts

Axis and Orbit Axis: Imaginary straight line through Earth between the North and South Pole, tilted at 23.5 degrees

Each planet orbits the Sun in a shape called an ellipse Kepler’s First Law Each planet orbits the Sun in a shape called an ellipse

Ellipse: An oval shape that is centered on two points (foci) or a single point (in the case of a circle)

Orbit The path of a celestial object or an artificial satellite as it revolves around another object

FYI-DO NOT WRITE! Did you know we’re spinning right now? The Earth rotates at 1000 mph at the equator The Earth rotates at about 700-900 mph here The Earth is also revolving around the sun at 67,000 mph Earth's Rotation Earth's Revolution

Rotation The Earth makes one complete turn every 24 hours (that’s 360 degrees) Earth rotates at 15 degrees of longitude per hour Earth rotates counterclockwise in the Northern Hemisphere Rotation causes the sun to appear to rise in the east and set in the west

Evidence of Rotation Foucault Pendulum: (DO NOT WRITE) a ball and wire is suspended and set into motion along a meridian. The pendulum will line up with different markings on the ground basically showing that the Earth is moving underneath the wire and ball) Foucault's Pendulum

More evidence Coriolis Effect: The curving of winds to the right in the Northern Hemisphere caused by Earth’s rotation Without rotation, winds would blow straight from areas of high pressure to areas of low pressure If you launch a rocket and do not account for the Earth rotating underneath the rocket, you will miss your target

Coriolis Effect Example (Do not write) If you flush a toilet in the Northern Hemisphere, the water will swirl to the left (counterclockwise). If you flush a toilet in the Southern Hemisphere, the water will swirl to the right (clockwise)… Take a look the next time you visit the loo!

Revolution Revolution: The orbital movement of an object around another object The Earth revolves 1 degree per day The Earth revolves once around the sun every 365.25 days

Proofs of Revolution Proofs: Parallax: Apparent shift of objects in the sky at different times of year The seasons (DO NOT WRITE.. JUST FYI- If we did not revolve, the Earth would not vary in tilting towards and away from the sun, meaning that seasons would not exist ->Side note: We’re actually 3 million miles closer to the Sun in January than in July!!!)