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This NASA Scientist Helps Prevent Mars from Contamination
The spacecraft has to be extremely clean. The entire spacecraft—that includes the rover, the heat shield, the descent stage, and back shell—must contain less than 500,000 bacterial endospores, or spores. Just to give you an idea, a teaspoon of seawater has ten times more bacteria.
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Discover the fascinating chemistry that makes our world and everything in it—including us.
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Can bringing predators—and fear—back into an ecosystem help restore its natural balance?
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Paleontologist Kirk Johnson explores the dynamic history—and future—of ice at the poles.
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Discover the science behind Leonardo da Vinci's masterpieces—and Mona Lisa's iconic smile.
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Amazing fossils reveal how mammals took over after an asteroid wiped out the dinosaurs.
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Discover why scientists and entrepreneurs alike have their sights set on the Moon again.
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New archeological evidence shows the stunning engineering of the Great Pyramid of Giza.