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How do the astronauts communicate in space if sound cannot travel in a vacuum?
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Can astronauts play musical instruments in space?
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Can I communicate faster than light?
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Can I listen to the SETI@home radio signal?
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How do astronauts communicate with their families from space?
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How much power is contained in a beam of light?
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What effect did compression waves have immediately following the Big Bang?
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Did a giant impact cause the Dark Ages? (Beginner)
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Is speed of light the same everywhere ? (Beginner)
How does Venus have sulphuric acid in it's clouds? (Beginner)
Earth's Bow Shock (Advanced)
How much does the Earth "wobble" on its orbit due to the Moon's gravity? (Intermediate)
Why is the sun red? During sunset, Northeastern US, Summer 2021 (Beginner)
Why do rays from Sun appear to converge at a point? (Beginner)
But seriously: what was there before the Big Bang? (Beginner)
How far can photons move freely in the early universe (Advanced)
How likely is it that the Solar System has had or will have a close encounter with another star? (Intermediate)
How do we know what we observe is x light years away? (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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How do you measure the distance between Earth and the Sun? (Intermediate)
Why do the planets orbit the sun? (Beginner)
At what speed does the Earth move around the Sun? (Beginner)
How long could life on Earth survive if the Sun stopped shining? (Beginner)
What are constellations used for? (Intermediate)
Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
What's going to happen on December 21st 2012? (Intermediate)
How does the location of sunrise and sunset change throughout the year? (Advanced)
Which planet is most similar to Earth? (Intermediate)
How are light and heavy elements formed? (Advanced)
How do you measure the distance between Earth and the Sun? (Intermediate)
Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
Why do the planets orbit the sun? (Beginner)
Which planet is most similar to Earth? (Intermediate)
How long could life on Earth survive if the Sun stopped shining? (Beginner)
At what speed does the Earth move around the Sun? (Beginner)
What is the difference between a "star" and a "sun"? (Beginner)
What's going to happen on December 21st 2012? (Intermediate)
How does the position of Moonrise and Moonset change? (Intermediate)
What are constellations used for? (Intermediate)
How do you measure the distance between Earth and the Sun? (Intermediate)
Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
How big is the Hubble Ultra Deep Field image? (Intermediate)
Which planet is most similar to Earth? (Intermediate)
Why do the planets orbit the sun? (Beginner)
How does the position of Moonrise and Moonset change? (Intermediate)
What are constellations used for? (Intermediate)
Why do we not have eclipses every month? (Beginner)
How long could life on Earth survive if the Sun stopped shining? (Beginner)
What is the difference between a "star" and a "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)
How do you measure the distance between Earth and the Sun? (Intermediate)
Is the Moon moving away from the Earth? When was this discovered? (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)
When was the last time all of the planets were aligned? (Beginner)
How long does it take for the Sun's light to reach us? (Beginner)
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