A neutron star (what remains after a Super Nova) is so dense that a portion of it the size of a sugar cube would weigh as much as all of humanity, or more than all the cars in the United States.
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Mars had an oxygen-rich atmosphere around 4 billion years ago
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If NASA sent birds into space they would soon die; they need gravity to swallow.
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MDIF, a New York based non-profit organisation, is planning to beam free Wi-Fi to the entire world from space.
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On Titan, Saturn's largest moon, the atmosphere is so thick and the gravity so low that humans could fly through it by flapping "wings" attached to their arms.
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