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Does the Moon rotate? Are there other moons that always keep one face toward their planet?
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Is Earth-moon tidal friction causing global warming?
(Intermediate)
Is the distance from the Earth to the Sun changing?
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Is the Moon moving away from the Earth? When was this discovered?
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The Moon slows the Earth's rotation, but how fast was it spinning billions of years ago?
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What would happen if we did not have a Moon?
(Intermediate)
Why are there active volcanos on Io?
(Intermediate)
Why do most moons orbit their planets at the equator?
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Why does the Earth only see one side of the Moon?
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Why is the Moon higher in the sky in winter and lower in the summer? (Beginner)
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What should I know about the upcoming Solar Eclipse? (2017)
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How far is each planet from Earth? (Intermediate)
How do you measure the distance between Earth and the Sun? (Intermediate)
At what speed does the Earth move around the Sun? (Beginner)
Why do airplanes take longer to fly West than East? (Intermediate)
Is the Moon moving away from the Earth? When was this discovered? (Intermediate)
What is the universe expanding into? (Intermediate)
Is the universe expanding faster than the speed of light? (Intermediate)
What would happen if the gravity on Earth was suddenly turned off? (Beginner)
Which planet is most similar to Earth? (Intermediate)
Can artificial gravity be created in space? (Intermediate)
When was the last time all of the planets were aligned? (Beginner)
What color is each planet? (Intermediate)
What is the significance of the Tropic of Cancer, Tropic of Capricorn, Arctic Circle and Antarctic Circle? (Beginner)
How far is each planet from Earth? (Intermediate)
How do you measure the distance between Earth and the Sun? (Intermediate)
At what speed does the Earth move around the Sun? (Beginner)
What is the difference between a "star" and a "sun"? (Beginner)
Why do the planets orbit the sun? (Beginner)
How does the location of sunrise and sunset change throughout the year? (Advanced)
Why do airplanes take longer to fly West than East? (Intermediate)
Why are the Moon and Sun sometimes orange or red? (Beginner)
What color is each planet? (Intermediate)
When was the last time all of the planets were aligned? (Beginner)
What is the significance of the Tropic of Cancer, Tropic of Capricorn, Arctic Circle and Antarctic Circle? (Beginner)
How far is each planet from Earth? (Intermediate)
How do you measure the distance between Earth and the Sun? (Intermediate)
At what speed does the Earth move around the Sun? (Beginner)
What is the difference between a "star" and a "sun"? (Beginner)
Why do the planets orbit the sun? (Beginner)
Why do airplanes take longer to fly West than East? (Intermediate)
What's going to happen on December 21st 2012? (Intermediate)
What color is each planet? (Intermediate)
At what speed does the Earth move around the Sun? (Beginner)
How far is each planet from Earth? (Intermediate)
Is the Moon moving away from the Earth? When was this discovered? (Intermediate)
How do you measure the distance between Earth and the Sun? (Intermediate)
Why do the planets orbit the sun? (Beginner)
How long does it take for the Sun's light to reach us? (Beginner)
What is the universe expanding into? (Intermediate)
When will Halley's Comet return? (Intermediate)
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