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How do we weigh objects in space?
(Beginner)
How do you calculate the lifetime of the Sun?
(Advanced)
How do you measure a planet's mass?
(Beginner)
How do you measure the mass of a star?
(Beginner)
How does a star take mass from another star?
(Intermediate)
How does the Sun compare to other stars?
(Beginner)
How far does a galaxy extend?
(Intermediate)
How many stars are there in our Galaxy (Milky Way)?
(Intermediate)
If gravity is a "curvature of space" rather than a force, why do a ball and bullet follow different paths?
(Intermediate)
If gravity isn't a force, how does it accelerate objects?
(Advanced)
If light has no mass, then what draws it into a black hole?
(Intermediate)
If photons have zero mass, why do they feel the effects of gravity?
(Advanced)
Is it true that the Sun burns off a billion tons of gas every 5 seconds?
(Beginner)
Is light of different colors affected differently by gravity?
(Intermediate)
Is the Earth slowly getting larger?
(Beginner)
Is the Moon hollow?
(Intermediate)
Is time travel possible?
(Beginner)
What are "blue stragglers" in globular clusters?
(Intermediate)
What are the requirements for being a planet?
(Beginner)
What causes a particle to decay?
(Intermediate)
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What is the universe expanding into? (Intermediate)
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What are constellations used for? (Intermediate)
Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
When will humans travel to Mars and revisit the Moon? (Intermediate)
How do we know what other planets (and stars, galaxies, etc.) are made of? (Intermediate)
How are planets affected by the Hot Ionised Medium? (Advanced)
What would happen to the Earth if an asteroid hit the Moon? (Intermediate)
Considering the motion of the Earth, the solar system, and the galaxy, how fast am I moving while lying in bed asleep? (Intermediate)
Is there really a 10th planet? (Beginner)
Is time travel possible? (Beginner)
Where does the name "Milky Way" come from? (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)
When was the last time all of the planets were aligned? (Beginner)
How does the location of sunrise and sunset change throughout the year? (Advanced)
Is speed of light the same everywhere ? (Beginner)
What was the bright, smoothly moving star that I saw? (Beginner)
Why is the sun red? During sunset, Northeastern US, Summer 2021 (Beginner)
Which planet is most similar to Earth? (Intermediate)
What are constellations used for? (Intermediate)
How does Venus have sulphuric acid in it's clouds? (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 was the bright, smoothly moving star that I saw? (Beginner)
How does the position of Moonrise and Moonset change? (Intermediate)
Which planet is most similar to Earth? (Intermediate)
What are constellations used for? (Intermediate)
How does the location of sunrise and sunset change throughout the year? (Advanced)
Why do we not have eclipses every month? (Beginner)
What is the difference between a "star" and a "sun"? (Beginner)
Why do the planets orbit the 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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