Why do we have seasons? Fold your paper into a Frayer model: 4 equal rectangles

The tilt of Earth’s axis causes seasons  Earth’s axis is tilted about 23.5 °

northern hemisphere June  The sun shines directly on the northern hemisphere in June southern hemisphere December  The sun shines directly on the southern hemisphere in December  That's why the seasons are different in each hemisphere! (CLICK HERE)(CLICK HERE) spring and fallfairly straight on the equator  In the spring and fall, the sun shines fairly straight on the equator, giving both hemispheres equal warming.

Let’s ‘ANIMATE’ season changes  McGraw Seasons Navigator McGraw Seasons Navigator

SUMMERSPRING WINTERFALL SEASONS  Vernal Equinox: “equal night”  Sun is at the equator  March 21 (ish)  Both hemispheres receive ‘about’ the same amount of light Sp

SUMMERSPRING WINTERFALL SEASONS Su  Summer solstice: “sun stands still”  Sun is at the most northern point of our planet  June 21 (ish)  Sun is highest in the sky  More light hours  Vernal Equinox: “equal night”  Sun is at the equator  March 21 (ish)  Both hemispheres receive ‘about’ the same amount of light Sp

SUMMERSPRING WINTERFALL SEASONS Su  Summer solstice: “sun stands still”  Sun is at the most northern point of our planet  June 21 (ish)  Sun is highest in the sky  More light hours  Vernal Equinox: “equal night”  Sun is at the equator  March 21 (ish)  Both hemispheres receive ‘about’ the same amount of light Sp  Autumnal Equinox: “equal night”  Sun is at the equator  September 21 (ish)  Both hemispheres receive ‘about’ the same amount of light F

SUMMERSPRING WINTERFALL SEASONS Su  Summer solstice: “sun stands still”  Sun is at the most northern point of our planet  June 21 (ish)  Sun is highest in the sky  More light hours  Winter solstice: “sun stands still”  Sun is at the most southern point of our planet  December 21 (ish)  Sun is lowest in the sky  Less light hours W  Vernal Equinox: “equal night”  Sun is at the equator  March 21 (ish)  Both hemispheres receive ‘about’ the same amount of light Sp  Autumnal Equinox: “equal night”  Sun is at the equator  September 21 (ish)  Sun Both hemispheres receive ‘about’ the same amount of light F

Earth’s orbit is NOT a perfect circle!  Earth orbits the sun in an ELLIPSE (oval)  Perihelion: The day that earth is closest to the sun  Perihelion: January 2 (ish)  Aphelion: The day that earth is farthest from the sun  Aphelion: July 3 (ish)

Common Misconception  People often think that when Earth is closer to the sun, it is SUMMER.  Look at this: EARTH’S ORBITEARTH’S ORBIT WRONG!

Credit to…(found from NetTrekker) 1) flash/seasons.swf 2) pluginpop.cgi?it=swf::800::600::/sites/dl/free/ /78778/Seasons_Nav.swf 3) science/physics/mechanics/orbit/perihelion_aphelio n.html&edu=high

Why do planets have seasons? 1. Why do planets have seasons? a. When a planet is closer to the sun, it will experience summer. When a planet is farther from the sun, it will experience winter. b. The tilt of a planet creates seasons because it receives direct or indirect sunlight. c. A planet experiences seasons as it rotates on its axis. d. A planet experiences seasons as the moon revolves around it. 2. The location at which Earth is closest to the sun is called a. perihelion. b. aphelion. c. vernal equinox. d. summer. 3. The location at which Earth is farthest from the sun is called a. perihelion. b. aphelion. c. summer solstice. d. winter. 4. Both the northern and southern hemispheres receive approximately 12 hours of daylight and 12 hours at what time? a. vernal equinox and autumnal equinox b. summer solstice and winter solstice c. vernal equinox and summer solstice d. autumnal equinox and winter solstice 5. Which of the following statements is NOT true? a. The sun is highest in the sky during the summer solstice. b. The sun is lowest in the sky during the winter solstice. c. The sun is at the equator during the autumnal equinox. d. The sun is highest in the summer equinox.