Mars had an oxygen-rich atmosphere around 4 billion years ago
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Pluto is smaller than Russia.
9
If two pieces of metal touch in space, they become permanently stuck together.
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There is a mass reservoir of water floating in space that is 100,000 times bigger than our sun and holds 140 trillion times more water than all of our oceans.
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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.
6
If you were to cry in space, the tears would form a bubble in your eye until it's so big it moves to another spot on your face.
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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.
13
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.
9