* Astronomy

Chile's huge open-pit copper mine goes underground

From above, it looks like a colossal amphitheatre carved from rock, or the vast crater from a meteorite that crashed into Chile's Atacama desert ages ago. Inside the world's largest open-pit copper mine, dump trucks as big as two-story houses work around the clock to haul hundreds of tons of rock and minerals 850 meters to the surface of this elliptical, seemingly endless, man-made hole. 
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