lpira/education/powerpoints/ seasons . ppt

1. www.lpi.usra.edu/education/powerpoints/seasons.ppt http://www.lpi.usra.edu/education/resources/standards/seasons.shtml students.kennesaw.edu/~kfitzge5/Weather%20and%20Seasons.ppt

2. ~Planets and Seasons~

4. In the Spring time, the air gets warmer. Spring is also a rainy time of year in some places. The rain helps plants to grow. The leaves on the trees are green. Spring

5. Summer is the warmest time. These days are hot and sunny. The leaves on the trees are green. Summer

6. Winter is known as the coldest time of the year. In some places, the temperature is cold enough for snow! The trees become very bare. In the really warm places, the leaves may stay green. Winter

7. This is the time of year when the air gets cooler. Some of the days are sunny and clear while other days are cloudy. The leaves on the trees turn to red, orange, and brown. Fall

8. This is when water moves into the air, to the land, and back into the air. The Water Cycle The Water Cycle LAND AIR

9. 1. The sun’s heat makes water evaporate or change into a gas. 6. The rain and melted snow flow into streams, lakes, and oceans. How the Water Cycle Works 5. The water drops become very heavy and fall as rain or snow. 2. This gas, or water vapor meets cool air. 4. The drops of water come together and form clouds. 3. The water vapor changes into tiny drops of water.

10. Different Types of Weather * Sunny * Rainy * Cloudy * Snowy * Stormy * Windy

11. By the Lunar and Planetary Institute For use in teacher workshops Seasons What do your students think causes the seasons? http://nix.ksc.nasa.gov/info

12. What Should I Wear?

13. What Causes Earth’s Seasons? • Earth’s axis is tilted 23.5 degrees – it always points in the same direction (Polaris, the North Star) as we orbit our Sun once a year • This tilt causes the hemispheres to alternate in the amount of our Sun’s light and heat they receive through the year http://www.lpi.usra.edu/education/skytellers/seasons/about.shtml

14. True color images December March June September http://www.nasa.gov/vision/earth/features/blue_marble.html

15. A more detailed view, showing various parallels of latitude, at the Equinoxes (the view is the same at both Equinoxes). (PrzemyslawIdzkiewicz, Wikipedia Commons)

16. http://cseligman.com/text/sky/seasons.htm The motion of the Earth around the Sun, showing how the Northern hemisphere is tilted toward the Sun on one side of the orbit, and away from the Sun on the other side of the orbit. (Wikipedia Commons)

17. Northern Hemisphere Summer More daylight hours, more direct sunlight http://www.lpi.usra.edu/education/skytellers/seasons/about.shtml

18. Earth’s view, at the summer solstice. • North Pole in "permanent" daylight,it isn't going anywhere, as the Earth rotates. • (PrzemyslawIdzkiewicz, Wikipedia Commons)

19. Summary of relationship of tilts to seasons (detailed discussion below):(1) If the planet has no tilt (Mercury, Venus, Jupiter), it has no seasons(2) If the planet has a tilt similar to ours (Mars, Saturn, Neptune), it has seasons similar to ours(3) If the planet has a tilt close to 90 degrees (Uranus, Pluto), it has extreme seasons Summary of relationship of tilts to seasons (detailed discussion below):(1) If the planet has no tilt (Mercury, Venus, Jupiter), it has no seasons(2) If the planet has a tilt similar to ours (Mars, Saturn, Neptune), it has seasons similar to ours(3) If the planet has a tilt close to 90 degrees (Uranus, Pluto), it has extreme seasons

20. Seasons on Other Planets • In some cases, the changing distances from the Sun will affect the seasons. • In others, the axial tilt will make a huge difference!

21. Earth’s orbit is almost a perfect circle • Earth is CLOSEST to our Sun (91 million miles) in winter—January 3 • Earth is farthest from on our Sun (94 million miles) in summer –July 4

22. Height of Sun for USA Winter: The Sun rises in the southeast, stays low in the sky, and sets in the southwest. Spring: The Sun rises due east, moves higher in the sky than in winter, and sets due west. Summer: The Sun rises in the northeast, travels high (near zenith), and sets in the northwest. Fall: The Sun rises due east, travels to a medium-height in the sky, and sets due west.

23. Seasons on Planets PlanetAxial Tilt Orbit Mercury 0° 88 days Venus 177° 224 days Earth 23° 365 days Mars 25° 686 days Jupiter 3° 12 years Saturn 27° 30 years Uranus 98° 84 years Neptune 30° 165 years

24. Mars’ Orbit and Seasons At vernal equinox, Mars is 145 million miles from the Sun At winter solstice, Mars is 128 million miles from the Sun At summer solstice, Mars is 153 million miles from the Sun At autumnal equinox, Mars is 134 million miles from the Sun Original images from http://photojournal.jpl.nasa.gov/index.html