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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)
Most Popular
- 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)
- What is the difference between a "star" and a "sun"? (Beginner)
- How can we see the Milky Way if we are inside it? (Intermediate)
- Why can't a plane fly slowly and let the Earth pass underneath? (Beginner)
- At what speed does the Earth move around the Sun? (Beginner)
- What do "homogeneity" and "isotropy" mean? (Intermediate)
- Which planet is most similar to Earth? (Intermediate)
- How does the position of Moonrise and Moonset change? (Intermediate)
- Why is looking out into space the same as looking back in time? (Beginner)
- 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 does the position of Moonrise and Moonset change? (Intermediate)
- Why do we not have eclipses every month? (Beginner)
- Why is the moon in a different place every night? (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)
- What are constellations used for? (Intermediate)
- What was the bright, smoothly moving star that I saw? (Beginner)
- How do you measure the distance between Earth and the Sun? (Intermediate)
- How big is the Hubble Ultra Deep Field image? (Intermediate)
- Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
- Which planet is most similar to Earth? (Intermediate)
- What are constellations used for? (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)
- Why do we not have eclipses every month? (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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