Presentation on theme: "Today’s Agenda… Bellringer: Identify each as rotation or revolution (this is not multiple choice) –A. Takes 24 hours –B. Spins on Axis –C. Takes 365 ¼."— Presentation transcript:
Today’s Agenda… Bellringer: Identify each as rotation or revolution (this is not multiple choice) –A. Takes 24 hours –B. Spins on Axis –C. Takes 365 ¼ days –D. Causes day and night Notes on Seasons
Moon Journal What did the moon look like last night?
Review! What causes day and night? –Earth’s rotation on its axis
Review! How long does it take for the Earth to revolve around the sun? –365 ¼ days
Review! What is an orbit? –The path the Earth travels around the sun –Oval shaped
Today’s Goals! I can explain why the Earth has seasons.
Seasons on Earth There are four seasons
Seasons on Earth Sunlight hits the Earth –At the equator sunlight hits directly –Closer to the poles, sunlight hits at an angle and energy from the sun is spread out –This explains why it is warmer at the equator than at the poles
Seasons on Earth The Earth has seasons because its axis is tilted as it moves around the sun –Tilted away from the sun for half of the year and toward the sun for the other half –When the North is tilted toward the sun they have summer and the South has winter –Seasons have nothing to do with Earth’s distance from the sun
Earth in June The North is: –Tilted toward the sun –Has more hours of daylight –Summer The South is: –Tilted away from the sun –Less hours of daylight –Winter
Earth in December The South is: –Tilted toward sun –Summer The North is: –Tilted away from sun –Winter
Solstices in the North Summer –Sun is directly overhead in the North –June 21 –Longest amount of daylight of the year Winter –Sun is directly overhead in the South –December 21 –Shortest amount of daylight of the year For the Southern Hemisphere, the dates are reversed.
Earth in March and September Halfway between solstices Neither hemisphere is pointed toward or away from the sun For two days of the year the noon sun is directly overhead at EQUATOR
Earth in March and September These days are known as an equinox Length of daylight and dark is about the same March 21 vernal (spring) equinox –Marks the beginning of spring September 23 autumnal equinox –Marks the beginning of fall
Exit Slip! What is the difference between a solstice and an equinox?