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Is the Sun always up for exactly 12 hours at the equator?
(Beginner)
Why doesn't the length of each day change much around the solstices?
(Intermediate)
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How do we know what parameters to use when simulating the collision of the Milky Way and Andromeda? (Advanced)
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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 can we see the Milky Way if we are inside it? (Intermediate)
How do you measure the distance between Earth and the Sun? (Intermediate)
How can the universe be "flat"? We're 3D! (Beginner)
How are light and heavy elements formed? (Advanced)
Why do the planets orbit the sun? (Beginner)
Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
How long could life on Earth survive if the Sun stopped shining? (Beginner)
What is the universe expanding into? (Intermediate)
At what speed does the Earth move around the Sun? (Beginner)
What would happen if an asteroid 10 kilometers across hit the Earth? (Beginner)
How can we see the Milky Way if we are inside it? (Intermediate)
How do you measure the distance between Earth and the Sun? (Intermediate)
What would happen if an asteroid 10 kilometers across hit the Earth? (Beginner)
Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
How long could life on Earth survive if the Sun stopped shining? (Beginner)
At what speed does the Earth move around the Sun? (Beginner)
Why do the planets orbit the sun? (Beginner)
Can artificial gravity be created in space? (Intermediate)
How does the position of Moonrise and Moonset change? (Intermediate)
What is the difference between a "star" and a "sun"? (Beginner)
What would happen if an asteroid 10 kilometers across hit the Earth? (Beginner)
How do you measure the distance between Earth and the Sun? (Intermediate)
How can we see the Milky Way if we are inside it? (Intermediate)
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)
What is the difference between a "star" and a "sun"? (Beginner)
Why do the planets orbit the sun? (Beginner)
How does the position of Moonrise and Moonset change? (Intermediate)
At what speed does the Earth move around the Sun? (Beginner)
Why are there high tides during a Full Moon? (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)
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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Physics
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The Theory of Relativity
People & Astronomy
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Space Exploration & Astronauts
The History of Astronomy
Astronomy in the Arts