Earth in Space...
Calenders
History
Seasons of the Earth
Ancient Egyptians figured out that they could plant plants near the river.
Stars locate in the sky, they are in different places every night
Could predict when is was going to flood using astronomy
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How Earth Moves
Earth moves through space in two major ways: Roatation and Revolution.
Rotation- A turning or moving about a central point.
Revolution- Following a path in space around another object.
Rotation.
The imaginary line that passes through Earth's center and the North and South poles in Earth's axis. The spinning of Earth on it's axis is called rotation.
Earth's rotation causes day and night
As Earth rotates eastward, the sun appears to move westward across the sky. It takes Earth about 24 hours to rotate once.
Revolution
In addition to rotating on its axis. Earth travels around the sun. Revolution is the movement of one object around another. One complete revolution of Earth around the sun is called a year. Earth follows a path, or orbit.
People of many different cultures have struggled to establish calendars based on the length of time that Earth takes to revolve around the sun.
The ancient Egyptians created one of the first calendars. Egyptians astronomers counted the number of days between each first appearance of the star Sirius in the morning.
The Romans borrowed the Egyptian calendar of 365 days. But in fact, Earth orbit the sun in about 365 1/4 days. This is why we have leap year, so we have 366 days.
Spring
Summer
Fall
Winter
The seasons
The cause of the seasons can be attributed to the tilt of the Earth's axis
In summer, we are tipped toward the Earth.
In winter we are tipped away from the sun.
Earth is tilted 23.5 degrees
Solstices- Two long sides are the solstices, two most extreme seasons, Summer, and Winter. June 21st, and December 21st.
Equinox- Fall and Spring, March and September
If there was no tilt we would only have Winter, and Summer.