Follow the Sun Background: Our Earth turns on its axis one rotation in 24 hours. This 24- hour period makes our day. However our Earth does not sit perpendicular to its spin. Instead it has a tilt of 23.5 degrees. This tip helps to produce our seasons. When the sun's rays strike at an angle, as in the winter, the temperature is lower. This is because the rays are spread over a larger area and can't provide as much heat. In the winter, the sun's rays have to pass through more of the Earth's atmosphere. When the sun's rays strike the Earth nearly straight down, as in summer, the energy is more concentrated and the temperature goes up. In the summer, the rays have fewer miles of atmosphere to pass through. Many students believe the Earth is closer to the Sun in the summer and farther away in the winter. The Earth is actually closer to the sun in the winter. The angle of the sun's rays determines the seasons not the distance to the sun. This activity helps to demonstrate how the earth and sun may appear from a view in space. Materials: Clear 2-quart bowl Large sheet of white paper Sharp pencil Overhead marking pen Compass Activity: Make an X in the center of the paper. This X will represent our Earth. Take all the materials outside. Find a level surface for the paper. Make sure the location receives sunlight throughout the day. Place the bowl (our atmosphere) upside down on the paper. Mark an x on the center of the bottom of the bowl with the overhead marker. Make sure the X on the paper is lined up under the x in the center of the bowl. Trace the edge of the bowl onto the paper to make it easier to line up. Using the compass determine North for your location. Mark North on the paper and on the bowl. Each hour, touch the side of the clear bowl with the tip of the pencil so that the shadow of the pencil's tip falls on the X on the paper. You can put a small 1,2,3 etc. beside each dot so you'll remember the order in which you made the observations. To get accurate results the bowl must sit in the same location and be lined up in the same way for each hourly (and monthly reading). After making four or five marks determine which direction the sun is moving. Repeat this activity each month to show the changes in the angle of the sun throughout the year. Use one color overhead marker from Sept through December and another color from January through June. If this is done on or about the 20th of each month you will see the results on the fall and spring equinox and the winter solstice. Copyright 1999-2004 Journey North. All Rights Reserved. Please send all questions, comments, and suggestions to jn-help@learner.org