The Sun and Moon appear to be the same size because the moon is 400 times smaller than the Sun, but 400 times closer to Earth.
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An international team of astronomers has spotted the farthest known gravitational lens and, as Albert Einstein predicted, it is a galaxy that deflects and intensifies the light of a much further object.
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It takes a photon 170,000 years to travel from the core of the Sun to the surface, but only 8 minutes to travel the rest of the way to Earth.
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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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It would take more than 150 years to drive a car to the sun.
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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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