The Earth By Miss O.
1 of 4 rocky planets not a considered a planet at this time
Five Things Make the Earth a “Habitable Planet” in the Universe! 1. The Earth’s distance from the sun is just right. The sun warms the Earth, and it is not too hot or too cold—it is just right.
About 4 times the diameter of the moon (8, 000 miles across) Diameter is the distance across the center of a round object.
2. The size of the Earth is perfect for maintaining the gravity we need so we don’t float away or get crushed. We can walk and run with ease. Many other planets don’t have the right amount of gravity for us to live there. Gravity is a force that pulls two objects together.
Much smaller than the sun! http://www.youtube.com/watch?v=x1w8hKTJ2Co&safety_mode=true&persist_safety_mode=1&safe=active To scale video It would take 109 Earths to stretch across the Sun, and it would take over one million Earths to "fill up" the Sun if it were hollow. Earth
Motion: Rotationearth spinning on its axis 1 rotation = 24 hours (1 day) http://www.youtube.com/watch?v=lkWyM-M8o0c&safety_mode=true&persist_safety_mode=1&safe=active
3. The Earth’s tilt on its axis is ideal for life.a. If it were tilted any more, the temperature would swing too much between super-hot summers and super-cold winters.b. If it were tilted any less, too much sunshine all year long would super-heat the equator and too little heat would reach the north and south regions. An axis is an imaginary line that runs through the center of a planet or other object.
Revolution: earth orbiting around the sun 1 revolution = 365 days (1 year)
As the Earth revolves around the sun, the axial tilt of Earth causes seasons.
Experiment Time! • Miss O. will model with a flashlight the seasons. With a white board, you will write whether the Northern Hemisphere is experiencing winter or summer.
4. The Earth has a magnetic shield around it that protects life from the sun’s harmful rays.
5. Liquid water is necessary for life to exist. The Earth is the only planet (we know of) with enough liquid water—consider the oceans, lakes, rivers, and streams.
The Earth has a protective atmosphere that blocks out most of the sun’s harmful rays. An atmosphere is the blanket of gases that surrounds a planet or moon.
Crust • 0 - 37 miles deep • The rock and dirt that you see is just a thin layer. • Even the oceans have a layer of crust beneath them.
Mantle • 22 – 1,790 miles deep • Thick layer of soft, hot rock
Outer Core • 1,790 – 3,160 miles deep
Inner Core • 3,160–3,954 miles deep