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Is the Sun always up for exactly 12 hours at the equator?
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Why doesn't the length of each day change much around the solstices?
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How do distant galaxies differ from those nearby? (Advanced)
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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)
What makes quantum mechanics and general relativity incompatible? (Advanced)
What are we doing about Space Junk?
What what a black hole merger look like from a telescope? (Advanced)
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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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If the universe is 13.8 billion years old, how can it be larger than 13.8 billion light years across? (Advanced)
Why do planets have elliptical orbits? (Beginner)
How much does the Earth "wobble" on its orbit due to the Moon's gravity? (Intermediate)
But seriously: what was there before the Big Bang? (Beginner)
Why do rays from Sun appear to converge at a point? (Beginner)
Why is the sun red? During sunset, Northeastern US, Summer 2021 (Beginner)
How does the position of Moonrise and Moonset change? (Intermediate)
Are there telescopes that can see the flag and lunar rover on the Moon? (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 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)
Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
Why do the planets orbit the sun? (Beginner)
How does the position of Moonrise and Moonset change? (Intermediate)
But seriously: what was there before the Big Bang? (Beginner)
At what speed does the Earth move around the Sun? (Beginner)
How much does the Earth "wobble" on its orbit due to the Moon's gravity? (Intermediate)
How are light and heavy elements formed? (Advanced)
Is the Moon moving away from the Earth? When was this discovered? (Intermediate)
What is the difference between a "star" and a "sun"? (Beginner)
How do you measure the distance between Earth and the Sun? (Intermediate)
Why do the planets orbit the sun? (Beginner)
How long could life on Earth survive if the Sun stopped shining? (Beginner)
How does the position of Moonrise and Moonset change? (Intermediate)
Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
Why is the moon in a different place every night? (Beginner)
At what speed does the Earth move around the Sun? (Beginner)
How are light and heavy elements formed? (Advanced)
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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