Photo courtesy NASA
NASA’s image of "Earth at Night" is familiar to most Americans. The image appears on posters and postcards, and in most geography textbooks. But how was this image made? And what does it tell us about where and how we live on Earth?
First of all, "Earth at Night" is not a single image, but rather a composite of hundreds of photos taken by low-altitude satellites that are able to detect light emitted by towns, cities, industrial sites, oil fields, and fires. Careful examination of the image reveals much about the distribution of people and their activities on Earth.
Examining the Image
a) Access the "Earth at Night" image online and project the image on a classroom screen, or alternatively, if a computer lab is available, have students working in small groups access the image. Provide students with blank world regional maps and world atlases.
b) Begin by clicking once to zoom in on the United States. (Clicking a second time will return the image to full size.) Have students compare the lights on the image to maps of the U.S. in the atlas in order to identify major urban areas. Have them label these urban areas on a blank map of the U.S., identifying major cities. Ask students to explain the uniform distribution of tiny dots of light in the Plains states (the grid pattern is a remnant of the township and range survey system used to divide land parcels in this area). Ask them to explain the dark areas on the image (dark areas are mountains, desert, or other areas with little or no population). Have them refer to their atlases to identify and label these areas on their maps.
c) Assign different groups the following regions: South America, Europe, Africa, Southwest Asia, South Asia, East Asia, and Southeast Asia and Oceania. Have them repeat the exercise above for these regions, recording what they observe on the appropriate regional map.
Extending the Activity
Point out to students that not all visible light comes from urban areas. In fact, oil field burn-off flares and fires from slash-and-burn agriculture are also visible.
d) Access an updated version of "Earth at Night" and open the image. Point out the bright yellow and red areas on this image. Have students use maps in their atlases to identify these areas and speculate what the colors represent (yellow areas are oil fields; red areas are agricultural burning).
National Geographic Bee Competitions
The state competition of the National Geographic Bee was held on March 27 in each state and the District of Columbia. Fifty-one state champs as well as champions from the United States Territories and Department of Defense schools will travel to National Geographic headquarters in Washington D.C. for the national championship on May 11 to 13. View the list of state Bee champions.
The national championship preliminary rounds will take place on Monday, May 11, in Washington, D.C. The national championship final rounds, featuring the top ten finalists and moderated by award-winning journalist Soledad O’Brien, will be held on Wednesday, May 13, at National Geographic’s Washington, D.C., headquarters. National Geographic Channel will air the final round of the National Geographic Bee Championship at 8 p.m. ET/PT on Friday, May 15, and on Wednesday, May 20, at 7 p.m. ET/PT on Nat Geo WILD. It will also air on public television stations; check local television listings for dates and times.
Gain a Global Perspective
The 2014 National Geographic Bee finalists gush about geography.
How to Help
Donations help fund schools to participate in the National Geographic Bee.
Teachers can use these activities in the classroom to prepare students for the bee!
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