The visors on NASA space suits have a layer of gold so thin—just 0.000002 inch thick—it’s translucent. The gold reflects ultraviolet light from the unfiltered sun while letting in visible light.

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How Many People Have Been to the Moon?

Even if you weren’t alive for the first Moon landing on July 20, 1969, you’ve probably seen footage of it, when astronaut Neil Armstrong famously declared, “That’s one small step for [a] man, one giant leap for mankind,” and Buzz Aldrin helped him plant an American flag on the lunar surface. And