Download Seasons1 - KC

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
The Four Seasons
Spring
Summer
Fall
Winter
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.
LAND
The
Water
Cycle
AIR
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.
5. The water drops become
very heavy and
fall as rain or snow.
4. The drops of water come
together and form clouds.
How the
Water
Cycle
Works
2. This gas, or water
vapor meets cool air.
3. The water vapor changes
into tiny drops of water.
Different Types of Weather
* Sunny
* Rainy
* Cloudy
* Snowy
* Stormy
* Windy
Seasons
By the Lunar and Planetary Institute
For use in teacher workshops
What do your students think causes the seasons?
http://nix.ksc.nasa.gov/info
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
December
March
June
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)
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)
Northern Hemisphere Summer
More daylight hours, more direct sunlight
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
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 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.
Seasons on Planets
Planet
Axial Tilt
Mercury
0°
Venus
177°
Earth
23°
Mars
25°
Jupiter
3°
Saturn
27°
Uranus
98°
Neptune
30°
Orbit
88 days
224 days
365 days
686 days
12 years
30 years
84 years
165 years
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