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Second Rock from the Sun
Venus, named for the Roman goddess, is the sixth largest planet in the solar system. No other planet approaches closer to Earth.
Caltech/JPL/NASA
Outside the Bowl
Fishes have been in existence for more than 450 million years, during which time they have evolved to fit into almost every conceivable type of aquatic habitat.
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A Medium of Personal Expression
By 1900, Auguste Rodin was considered less a sculptor than an entrepreneur of sculpture.
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Prenatal Development
In humans, the period from the formation of an embryo, through the development of a fetus, to birth is characterized by a series of remarkably complex and highly coordinated processes.
Black History Month 
Historian Carter G. Woodson helped conceive a weeklong commemoration of the history and achievements of African Americans in 1926; in 1976, the celebration was expanded to all of February.
Great Zimbabwe
Now an extensive stone ruin, Great Zimbabwe was an African Iron Age city that once supported a Shonapopulation of 10,000 to 20,000 and was the heart of a thriving trading empire.
Valentine's Day
This romantic holiday has its origins in the Roman festival of Lupercalia.
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