Mars had an oxygen-rich atmosphere around 4 billion years ago
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An organisation called Mars One is planning to establish a permanent colony of humans on Mars by 2023.
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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.
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There is a mysterious and loud radio signal known as 'the space roar' that has yet to be explained.
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Pluto is smaller than Russia.
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Earth is the only planet in our solar system that's not named after a god or goddess.
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Jupiter has radio storms so strong that they can be picked up and heard by an AM radio.
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