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I’ve heard that most of Earth’s water came from comets, but where did all the water in those comets come from?

Thomas Kumiega Sr., Moosup, Connecticut
Blue-marble
Actually, comets may not be the most important source of Earth’s water. Computer simulations show that the scattering of comets inward from the realm of the giant planets was inefficient, and Jupiter and Saturn scattered most of these icy . . .

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