Earth's Movement (Topic 11, Lesson 1)

​How does Earth's motion affect the amount of daylight

and seasons?

Why do Earth and the moon remain in orbit?

Guiding Questions:

Literacy: Cite textual evidence.

Math: Analyze quantative relationships.

An axis is an imaginary line an object turns around. This imaginary line runs directly through the object's center, from the north to the south poles. Although we can't feel the Earth spinning, it makes one complete turn, each day, around its own axis.

​​Axis

​The action of rotating around an axis or center.

Rotation

​

The spinning of the earth is called rotation. It takes the earth abut 24 hours, or one day, to make one complete rotation. At the same time, the earth is moving around the sun. This is called a revolution. It takes a little over 365 days, or one year, for the earth to make one full revolution around the sun.

​​Revolution

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An orbit is the path of an object around a particular point in space, for example the path the Moon takes around the Earth.

​​orbit

​A solstice is a moment in the year when the Sun's apparent path is farthest north or south from Earth's Equator. There are two solstices each year—one in December and one in June.

solstice

​An equinox occurs when the position of the Sun is exactly over the Equator. When this happens, the hours of daylight and the hours of darkness are about equal almost everywhere on Earth. Equinoxes take place twice a year.

​​equinox

​An invisible force that pulls objects toward each other. Earth's gravity is what keeps you on the ground and what makes things fall.

Gravity

It states that every celestial body in the universe attracts every other celestial body. This attraction is due to a force (gravity) that depends on the mass of each body and on the distance between the bodies.

​​Law of Universal gradation