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The Milky Way Galaxy is the Galaxy star system where the solar system, including 120 billion stars and plenty of star clusters(星团), Its more than 100,000 light years in diameter（直径）, Center thickness of about 12,000 light years.
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solar system
• There are eight planets in our solar system. They're Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
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And the Earth is our home. We're living on the Earth, and it is the most beautiful in the solar system. It has lots of water and plants. And the moon is the Earth's partner. It goes around the Earth. And other planets are very far from the Earth. So the people can't reach them and none of them has an environment with air. The people also can't live in them.
• The universe is a huge wide-open space that holds everything from the smallest particle to the biggest galaxy(星系) . No one knows just how big the Universe is.
Thentists believe that about 13.7 billion years ago, a powerful explosion called the Big Bang happened. This powerful explosion set the universe into motion and this motion continues today. Scientists are not yet sure if the motion will stop, change direction,. or keep going forever. 2
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There is much beautiful and magic view in the universe.
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A Comet
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Black hole
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Horsehead Nebula
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• Rosette Nebula
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Galaxies, is the stars in the universe “ island ”, it is one of the largest and most beautiful celestial system（天体系 统) in the universe. To date, about 100 billion galaxies have been observed in the universe. Some of them we have close, some very far away, the furthest galaxy known today almost 15 billion light years away from us.