"Earth Viewer" is an interactive Web program that animates the patterns of the day and night cycle as they occur all over the globe. To investigate "Earth Viewer," bring your journal to the computer and go to the Museum's Antarctica resources Web site at:
http://www.amnh.org/education/resources/rfl/web/antarctica/earthviewer/
To conduct your investigation, work as scientists do—predict what you may discover, make observations, and record what you see. Look for patterns. Afterwards, offer hypotheses to explain those patterns. Don't worry if your hypotheses are sketchy right now; any testable hypothesis is a valid starting point. When scientists test their hypothesis and discover that their observations and data do not match their hypothesis, they redefine their investigation by improving the test and gathering more data, or refining the original hypothesis based on the new data before testing again. In your investigation, you can return to the interactive if you need to observe more details. Then revise your hypothesis or develop a new one based on each new round of observations.
To complete your understanding of the day and night cycles, check out the images of the night cycle projected on different maps of Earth at:
http://www.fourmilab.ch/earthview/
Take a close look at the images on your screen. The light areas show where it is light on Earth at a particular time, and the dark areas show where it is dark. The time scale marks the time of year when this pattern is happening.
If you're working with a team, discuss your observations with your teammates. In your own journal, remember to record your observations about the day and night patterns—both at your home location and at the poles. Use the questions below to guide your investigation.
- Find the approximate area on the globe where you live. What do you observe about the light and dark patterns there? What changes do you observe? When do they occur? Do your observations match with the daylight patterns that you actually experience in your area?
- Focus on the polar regions. What do you observe about the light and dark patterns at the poles? At what time of the year do changes occur? Is there also a daily light and dark cycle?
- How can you explain these patterns? Include drawings in your journal to illustrate your hypothesis. Your drawings should include the Earth and the Sun, as well as text to identify locations on the globe or times of day/night/year.