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What are "blue stragglers" in globular clusters?
(Intermediate)
What would happen if two stars collided?
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What is a Cepheid variable? (Intermediate)
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What makes certain lunar eclipses so special? (Beginner)
Why is Earth's core molten? (Intermediate)
What will happen to Earth's tides as the moon moves away from us? (Intermediate)
How can spiral galaxies keep their shape? (Advanced)
Does a black hole have a "surface"? (Intermediate)
How can you link telescopes to make a bigger "effective telescope"? (Intermediate)
What should I know about the upcoming Solar Eclipse (2017)? (Beginner)
Do galaxies that are receding from us faster than the speed of light disappear from our observations? (Intermediate)
Why are astronomers interested in gravitational waves? (Intermediate)
Can two galaxies move away from each other faster than the speed of light? (Intermediate)
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What is the universe expanding into? (Intermediate)
What do I need to do to become an astronomer? (Beginner)
What's the difference between astronomy and astrology? (Beginner)
Why is looking out into space the same as looking back in time? (Beginner)
Can we find the place where the Big Bang happened? (Intermediate)
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Can artificial gravity be created in space? (Intermediate)
What color is each planet? (Intermediate)
How far is each planet from Earth? (Intermediate)
How does the location of sunrise and sunset change throughout the year? (Advanced)
What is the significance of the Tropic of Cancer, Tropic of Capricorn, Arctic Circle and Antarctic Circle? (Beginner)
What is the difference between a "star" and a "sun"? (Beginner)
Why do airplanes take longer to fly West than East? (Intermediate)
Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
Why do the planets orbit the sun? (Beginner)
How do you measure the distance between Earth and the Sun? (Intermediate)
What color is each planet? (Intermediate)
How far is each planet from Earth? (Intermediate)
What is the difference between a "star" and a "sun"? (Beginner)
What is the significance of the Tropic of Cancer, Tropic of Capricorn, Arctic Circle and Antarctic Circle? (Beginner)
Can artificial gravity be created in space? (Intermediate)
Why are the Moon and Sun sometimes orange or red? (Beginner)
At what speed does the Earth move around the Sun? (Beginner)
How does the location of sunrise and sunset change throughout the year? (Advanced)
Is the Moon moving away from the Earth? When was this discovered? (Intermediate)
Why do airplanes take longer to fly West than East? (Intermediate)
What color is each planet? (Intermediate)
How far is each planet from Earth? (Intermediate)
What is the significance of the Tropic of Cancer, Tropic of Capricorn, Arctic Circle and Antarctic Circle? (Beginner)
What is the difference between a "star" and a "sun"? (Beginner)
When was the last time all of the planets were aligned? (Beginner)
Can artificial gravity be created in space? (Intermediate)
Is the Moon moving away from the Earth? When was this discovered? (Intermediate)
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 do the planets orbit the sun? (Beginner)
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)
What is the significance of the Tropic of Cancer, Tropic of Capricorn, Arctic Circle and Antarctic Circle? (Beginner)
How long does it take for the Sun's light to reach us? (Beginner)
When was the last time all of the planets were aligned? (Beginner)
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