As the World Turns How does our journey through space cause days, years, and seasons?

As the As the World TurnsWorld Turns

How does our journey through How does our journey through space cause days, years, and space cause days, years, and

seasons?seasons?

Earth rotates on its axis once every 24 hours. We call this one day.

When your part of the earth faces the sun, you experience day. What happens to cause night?

Sun appears to rise in the east and set in the west because the Earth turns on its axis from west to east.

The path the Earth takes around the sun is called it’s revolution. It takes us 365.24 days to travel around the sun. We revolve around

the sun counterclockwise.http://members.shaw.ca/len92/earth_revolution.gif

Moving through SpaceMoving through Space

The Earth revolves around the Sun at a The Earth revolves around the Sun at a rate of about 67,000 miles per hourrate of about 67,000 miles per hour

We are also moving through space with We are also moving through space with our solar system and the Milky Way our solar system and the Milky Way Galaxy Galaxy

We don’t feel how fast we are moving We don’t feel how fast we are moving because we have no way to sense the because we have no way to sense the movementmovement

• Are caused by the tilt of the Earth’s axis, which is at an angle of 23.5 degrees

• Each season lasts 3 months

• Equator is the line that divides the Northern and Southern Hemispheres

• The hemisphere tilted toward the sun gets more direct light

•There are four special times during the year.

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• Summer Solstice – sun’s rays hit as far north as the tilt will allow – occurs in the month of June

• Winter Solstice – sun’s rays hit as far south as the tilt will allow – occurs in the month of December

The Summer and Winter Solstices have been important to mankind for a long time. Stonehenge is aligned to measure the solstices.

Vernal Equinox in March and the Autumnal Equinox in September; Equinox means

“equal night”. These were considered the two days of the year where daylight and

nigh time hours were equal. Now refers to the days the center of the sun is directly

above the equator.

Many people believe we have summer because we are closer to the sun in the summer. Look at the diagram and explain why they are wrong!