Earth & Seasons: Notes

Earth & Seasons: notes 1. About ______, when the Earth was still very young, it was 1. ______2.______OBJECTIVE:. I will be able to: 2. As the cloud of dust and gas collapsed when ______the universe was forming, the solar system did _____ not form uniformly, ______, hence the tilting of the planets What is a season? • One of the major divisions of the year, ISN pg 124. generally based on ______. • One of the four natural divisions of the What does the tilt do? year, • It allows the sun’s rays to ______, ______, ______and ______and for longer periods of ______in the North and South time on some locations than other places of Earth Why are there seasons? The Earth has changes in seasons because Earth's orbit is in the shape of an ellipse, so it Sunlight Reaching Earth at… gets closer or further away from the sun as it  Equinox:______orbits the sun. ____ CIRCLE ONE: is the above statement… Right or Wrong? ______Ultimate Cause of Seasons  Solstice: • Earth’s axis is _____ oriented straight ______up and down from the ______• Instead, Earth is tilted from straight up Again, why are there seasons? and down by an angle of ~______. ______+______=______– Actually the angle ranges from 22 ____ to 24.5 degrees – Why do we have days? Why is it 23.5°? • We have day and night because the • No one knows… Earth rotates on its axis. • Astronomers have different theories: Day versus Night When where you are is pointed ______– this gives the North Pole 24 the Sun, it is day. Then the Earth rotates you hours of daylight for about 6 ______from the Sun, and it is night. months, while the South Pole is plunged into darkness Tilt of Earth and Days – on the equator, the sun is always • The length of a day changes because nearly overhead, so the days are ______more constant with approximately ______of daylight and ______of darkness ______- everyday ______

• The length of a day depends on where you are on the earth – sometimes the ______points towards the sun, while the ______points away Earth Models : Showing how Seasons Occur

Draw a picture of your earth model below. Be sure to label: equator, axis and the Northern and Southern hemispheres.

• 1. Explain how your model shows how the seasons change as the earth spins and rotates on it’s axis • 2. Explain how it can be summer in the Northern Hemisphere while it is winter in the Southern Hemisphere.

• 3. Describe what earth’s climate would be like if the earth didn’t have a 23.5 degree tilt. Would we have seasons? Why or why not?