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!What calculations go into predicting eclipses?
(Advanced)
But seriously: what was there before the Big Bang?
(Beginner)
Can two lunar eclipses occur in the same month?
(Advanced)
Can we look back in time and see our galaxy forming?
(Intermediate)
Can we make a movie of the Milky Way galaxy's rotation?
(Beginner)
Can you tell time by the Big Dipper?
(Beginner)
Could someone travel the universe in his or her own lifetime?
(Beginner)
Could we be seeing dead stars?
(Beginner)
Did time go slower just after the Big Bang?
(Advanced)
Do we have to worry about relativity when studying galactic objects?
(Intermediate)
Do we really observe the edges of galaxies at different epochs?
(Advanced)
How can I calculate the position or path of the Sun for a given time and location?
(Intermediate)
How can I watch the Perseid meteor shower?
(Beginner)
How do I maximize my chances of seeing shooting stars?
(Intermediate)
How do sunrise and sunset times change with altitude?
(Intermediate)
How is the time of sunrise calculated?
(Intermediate)
How long does it take for the Sun's light to reach us?
(Beginner)
If clocks run slow in a gravitational field, how can we know the true age of the Solar System and Universe?
(Intermediate)
If Mars is only about 35-60 million miles away at close approach, why does it take 6-8 months to get there?
(Intermediate)
If the Earth's rotation period is less than 24 hours, why don't our clocks fall out of sync with the Sun?
(Intermediate)
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But seriously: what was there before the Big Bang? (Beginner)
How far can photons move freely in the early universe (Advanced)
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What makes quantum mechanics and general relativity incompatible? (Advanced)
What are we doing about Space Junk?
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What is the universe expanding into? (Intermediate)
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Why is the sun red? During sunset, Northeastern US, Summer 2021 (Beginner)
Why do rays from Sun appear to converge at a point? (Beginner)
How do we know what we observe is x light years away? (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)
But seriously: what was there before the Big Bang? (Beginner)
What is the universe expanding into? (Intermediate)
What makes quantum mechanics and general relativity incompatible? (Advanced)
How much does the Earth "wobble" on its orbit due to the Moon's gravity? (Intermediate)
What are we doing about Space Junk?
What is the difference between a "star" and a "sun"? (Beginner)
How does the position of Moonrise and Moonset change? (Intermediate)
How do you measure the distance between Earth and the Sun? (Intermediate)
Why do the planets orbit the sun? (Beginner)
How are light and heavy elements formed? (Advanced)
At what speed does the Earth move around the Sun? (Beginner)
Why is the sun red? During sunset, Northeastern US, Summer 2021 (Beginner)
What is the universe expanding into? (Intermediate)
But seriously: what was there before the Big Bang? (Beginner)
Why is the moon in a different place every night? (Beginner)
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 does the position of Moonrise and Moonset change? (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)
But seriously: what was there before the Big Bang? (Beginner)
Is the Moon moving away from the Earth? When was this discovered? (Intermediate)
What is the universe expanding into? (Intermediate)
What was the bright, smoothly moving star that I saw? (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)
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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