Site hosted by Angelfire.com: Build your free website today!
 

Earth's Seasons
Earth's Rotation  

As the earth revolves around the sun it is spinning or rotating like a top. It spins around an imaginary line called its axis.  

The earth makes one complete rotation in 23 hours and 56 minutes.  


 
 

 
Earth's Revolution  

Earth revolves once around the sun in about 365 days (one year.) The path it follows is known as its orbit. During its elliptical orbit, its distance from the sun changes.  The closest point is earth's perihelion.  The farthest point is its aphelion. 
 
 

 

 
Seasons 

Because of the tilt of the earth's axis (23.5°), the amount of sunlight falling on a region of the earth changes throughout the year.  

Solstices and Equinoxes  

zenith - highest point in the sky, directly overhead  
solstice - when the noon sun is directly overhead  
equinox - when the noon sun is directly over the equator  
 
 
Points to remember about the seasons:
 
Because of the tilt of the earth's axis (23.5°), the amount of sunlight
falling on a region of the earth changes throughout the year.

The tilt of the Earth’s axis causes seasons.
 

•Our summer begins when direct rays of the sun fall on the northern hemisphere. (longer days)(23 1/2 ° N)
 
•Our winter begins when direct rays of the sun fall on the southern hemisphere (shorter days) (23 1/2 ° S)
 
•First day of summer – summer solstice (longest day)
•First day of winter – winter solstice (shortest day)
 
•First day of spring – Vernal (Spring) Equinox
•First day of fall – Autumnal (Fall) Equinox
 
•Equinox - equal hours of day and night on the first day of spring and fall
 
Go back to Classpage

 

http://liftoff.msfc.nasa.gov/News/2001/News-AutumnalEquinox.asp

http://www.enchantedlearning.com/subjects/astronomy/planets/earth/Seasons.shtm

This site is called Here Comes the Sun.  It has lots of info about seasons
http://vortex.plymouth.edu/sun/sun1.html

Other links:
http://windows.arc.nasa.gov/cgi-bin/tour_def/the_universe/uts/seasons1.html