Changing Seasons Matchcard
The Changing Seasons MatchCard explores the weather in the northern and southern hemispheres in relation to the earth's revolution around the sun..
The Four Seasons
Objective: Describe why the seasons change with the revolution of the Earth around the sun.
Print the Changing Seasons MatchCard (below) as a worksheet after the demonstration.
The Earth's Revolution Around the Sun
Use a globe and a light source to demonstrate this concept.
- First review how the earth rotates on its axis (in 24 hours) and revolves around the sun (in one year.)
- If you have a globe on a base, point out that it is tilted and not straight up and down. If you are using an inflatable globe, demonstrate that.
- Have the globe facing toward the light source so that it is summer in the northern hemisphere. The North Pole will be closest to the "sun." Ask whether it would warmer in the north or the south. (north)
- Move 180% to the other side of the light source. At this point, the South Pole should be facing towards the "sun." Ask whether it would be warmer or colder in the north or south. (south)
- Point out that we have opposite seasons in the northern and southern hemispheres. Have the students walk around the sun and name the seasons of each hemisphere.
23.5 Degrees
- Hold the globe straight up and down and ask if there would be seasons if the Earth was aligned this way. (no)
- Show the Earth again at the 23.5 degree tilt. Explain that it is tilted 23.5%.
- If your student has some understanding of angles, this activity might be helpful to them to grasp how much 23.5 degrees actually is.
- Take a circle made out of paper. A cheap paper plate works well for this activity. Cut the edges off so it is a flat circle. It also works well to trace a dinner plate around a piece of paper.
- Fold it in half. It is now a 180 degrees half circle.
- Fold it in half again. It is now 90 degrees - 1/4 circle.
- Fold in half again. Now it is 45 degrees - 1/8 circle.
- Fold in half one more time. Now it is 22.5 degrees - 1/16 circle.
- Now open up the paper to show the whole circle with 16 segments. Each segment is 22.5 degrees.
- Compare 22.5 degrees with 23.5 degrees. The angle of the Earth's tilt would be just a tiny fraction of a slice larger than the 22.5 degree angle.
- Carefully cut out one segment, cutting on the OUTSIDE of the line. This will probably get very close to the 23.5 degree angle.
- If you have an inflatable globe or other globe without a base, use the angle to tilt the Earth.
Solstice and Equinox
Explain that there are two soltices a year. At that point the poles are tilting the furthest or the closest to the sun.
The date of the soltices change very slightly every year.
- June 21st is the most common date for the summer soltice for the northern hemisphere and winter soltice for the southern hemisphere.
- December 21st is the most common date for the winter soltice for the northern hemisphere and summer soltice for the southern hemisphere.
Equinox refers to the two dates when the sun is midway between the soltices.
- March 20 is the most common date for the spring soltice for the northern hemisphere and fall soltice for the southern hemisphere
- September 22 is the most common date for the fall soltice for the northern hemisphere and spring soltice for the southern hemisphere
If your globe has a stand, ask your student to place the soltice as accurately as possible to the exact point.
Point out the diagrams on the Changing Seasons MatchCard and let the students place the information pieces in the correct place (download below.)
Using the Changing Seasons Matchcard
This is the first Matchcard of the Weather Unit Study. You can download the Changing Seasons Matchcard here.
The student matches the seasons with the diagram of the earth and sun..
The second page is the Instructor's Guide with the correct answers.
The third page has the Information Pieces. Student's cut them apart and place them in the correct place on their copy of the Matchcard (first page.)
For more information on how to use the Matchcards, see the MatchCard Science Instructor's Guide.
MatchCard Science
The activities and illustration above are from MatchCard Science, a homeschool science unit study.
For the complete Weather Unit Study follow this link. This unit study provides:
- hands-on demonstrations
- MatchCard reviews to master the material
- suggestions for science projects to complete
- instructions on a complete unit study curriculum
Currently this curriculum is under-going revision. We are providing free access to the unit study, with the desire that you will provide feedback as you are field testing the materials.
Science Notebook
If you are just using this single project, and are not in need of a full unit study, you might want your student to complete a science notebook entry for this project.
Return from the Changing Seasons Matchcard to the MatchCard Science Main Page.
|
