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

Spring 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.

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

Winter 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.

Fall 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.

The Water Cycle This is when water moves into the air, to the

land, and back into the air.

The Wate

r Cycl

e

LAND AIR

How the WaterCycle Works

1. The sun’s heat makes water evaporate or change into a gas.

3. The water vapor changes into tiny drops of water.

4. The drops of water come together and form clouds.

5. The water drops become very heavy and

fall as rain or snow.

6. The rain and melted snow flow into streams,lakes, and oceans.

2. This gas, or water vapor meets cool air.

Different Types of Weather* Sunny * Rainy

* Cloudy * Snowy

* Stormy * Windy

Seasons

What do your students think causes the seasons?

http://nix.ksc.nasa.gov/info

By the Lunar and Planetary Institute

For use in teacher workshops

Weather How to Prepare

Hot Days Wear loose, light clothing. Drink plenty of water. Stay indoors or in the shade.

Cold Days Wear layers if dark clothing. Wear mittens and a hat. Keep your skin dry!

Sunny Days Use sunscreen. Wear a hat and sunglasses.

Rainy Days Wear a raincoat and rain boots. Wear a hat or use an umbrella.

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

True color images

June

December

March

September

http://www.nasa.gov/vision/earth/features/blue_marble.html

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

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)

http://cseligman.com/text/sky/seasons.htm

More daylight hours, more direct sunlight

Northern Hemisphere Summer

http://www.lpi.usra.edu/education/skytellers/seasons/about.shtml

Earth’s view, at the summer solstice.

North Pole in "permanent" daylight, it isn't going anywhere, as the Earth rotates. (Przemyslaw Idzkiewicz, Wikipedia Commons)

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

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!

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

Height of Sun for USAWinter: 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.

Seasons on PlanetsPlanet Axial Tilt OrbitMercury 0° 88 days Venus 177° 224 daysEarth 23° 365 days Mars 25° 686 days Jupiter 3° 12 yearsSaturn 27° 30 yearsUranus 98° 84 yearsNeptune 30° 165 years

Mars’ Orbit and Seasons

At summer solstice, Mars is 153 million miles from the Sun

At autumnal equinox, Mars is 134 million miles from the Sun

At winter solstice, Mars is 128 million miles from the Sun

At vernal equinox, Mars is 145 million miles from the Sun

Original images from http://photojournal.jpl.nasa.gov/index.html