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Blue Stragglers
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What are "blue stragglers" in globular clusters?
(Intermediate)
What would happen if two stars collided?
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Why are craters round? (Beginner)
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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)
What is a graviton? (Intermediate)
Why are there high tides during a Full Moon? (Intermediate)
Why is Neptune still considered a planet when Pluto crosses its orbit? (Intermediate)
Could there be objects orbiting interior to Mercury? (Intermediate)
Have the inner planets cleared their neighborhood? (Intermediate)
What caused the Big Bang and created the Universe? (Beginner)
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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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Why are the Moon and Sun sometimes orange or red? (Beginner)
Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
Why can't a plane fly slowly and let the Earth pass underneath? (Beginner)
What color is each planet? (Intermediate)
What color are meteors? (Beginner)
What is the difference between a "star" and a "sun"? (Beginner)
When was the last time all of the planets were aligned? (Beginner)
Why do airplanes take longer to fly West than East? (Intermediate)
Can we see dead stars with the naked eye? (Beginner)
Is the Moon moving away from the Earth? When was this discovered? (Intermediate)
What color is each planet? (Intermediate)
What is the significance of the Tropic of Cancer, Tropic of Capricorn, Arctic Circle and Antarctic Circle? (Beginner)
Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
What is the difference between a "star" and a "sun"? (Beginner)
Why can't a plane fly slowly and let the Earth pass underneath? (Beginner)
Can artificial gravity be created in space? (Intermediate)
Why do airplanes take longer to fly West than East? (Intermediate)
How far is each planet from Earth? (Intermediate)
What is that ring (or rainbow) around the moon? (Beginner)
At what speed does the Earth move around the Sun? (Beginner)
What color is each planet? (Intermediate)
Why do stars twinkle? (Beginner)
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)
Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
Why do airplanes take longer to fly West than East? (Intermediate)
Can artificial gravity be created in space? (Intermediate)
How far is each planet from Earth? (Intermediate)
Why can't a plane fly slowly and let the Earth pass underneath? (Beginner)
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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