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Can "tired light theory" explain the observed redshifts of galaxies?
(Intermediate)
Can gravitational lensing from intervening galaxies cause the observed ripples in the Cosmic Microwave Background?
(Advanced)
Can we look back far enough in time to see the Big Bang?
(Beginner)
Could photons be dark matter?
(Intermediate)
Could the Universe have expanded faster than the speed of light at the Big Bang?
(Intermediate)
How big is the Universe?
(Intermediate)
How do we know the age of the Universe and the Earth?
(Intermediate)
What makes up most of the Universe?
(Beginner)
What's the difference between dark matter and dark energy?
(Intermediate)
Where, in relation to the entire universe, is the Milky Way located?
(Intermediate)
Why is the Cosmic Microwave Background not absorbed by interstellar hydrogen?
(Advanced)
Why is the WMAP picture of the CMB an ellipse?
(Intermediate)
Wouldn't the Big Bang theory be considered a hypothesis and not a theory?
(Intermediate)
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Do asteroids ever do anything good in the Solar System? (Beginner)
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What what a black hole merger look like from a telescope? (Advanced)
Do galaxy mergers have a major impact on star formation rates within the galaxies? (Intermediate)
Our universe is still expanding, does that mean things in our daily life are expanding? (Intermediate)
What was the bright, smoothly moving star that I saw? (Beginner)
What happened to the Arecibo Telescope? (Beginner)
Can I buy or name a star? (Beginner)
If I were hypothetically wearing a spacesuit and sitting on one of the Voyager space probes at their current positions in space, how much light would I have? (Intermediate)
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)
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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 are light and heavy elements formed? (Advanced)
What is the difference between a "star" and a "sun"? (Beginner)
Why do the planets orbit the sun? (Beginner)
How do you measure the distance between Earth and the Sun? (Intermediate)
How does the position of Moonrise and Moonset change? (Intermediate)
Can artificial gravity be created in space? (Intermediate)
How long could life on Earth survive if the Sun stopped shining? (Beginner)
Which planet is most similar to Earth? (Intermediate)
What color is each planet? (Intermediate)
Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
How do you measure the distance between Earth and the Sun? (Intermediate)
How does the position of Moonrise and Moonset change? (Intermediate)
How long could life on Earth survive if the Sun stopped shining? (Beginner)
What is the difference between a "star" and a "sun"? (Beginner)
Why do the planets orbit the sun? (Beginner)
Can artificial gravity be created in space? (Intermediate)
Which planet is most similar to Earth? (Intermediate)
How are light and heavy elements formed? (Advanced)
Why is the moon in a different place every night? (Beginner)
Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
How do you measure the distance between Earth and the Sun? (Intermediate)
What is the difference between a "star" and a "sun"? (Beginner)
How long could life on Earth survive if the Sun stopped shining? (Beginner)
Why do the planets orbit the sun? (Beginner)
Which planet is most similar to Earth? (Intermediate)
How are light and heavy elements formed? (Advanced)
How does the position of Moonrise and Moonset change? (Intermediate)
At what speed does the Earth move around the Sun? (Beginner)
Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
Can artificial gravity be created in space? (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)
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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