PHOTOS & VIDEOS
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VIDEO
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VIDEO
Mighty Monarchs: Migration
Learn more about our September 30, 2011 cover story on the migration of monarch butterflies
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VIDEO
Infinity and Beyond
After 34 years in space, NASA's Voyager probes will soon cross the boundary of our solar system into interstellar space
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SLIDE SHOW
The Everglades
Everglades National Park, at the southern tip of Florida, is the largest wetland in the United States. A wetland is a habitat that is regularly wet or flooded, such as a marsh, swamp...