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Are there any 'lonely galaxies'?
(Beginner)
Has anyone made a map of the Milky Way?
(Beginner)
How can we see the Milky Way if we are inside it?
(Intermediate)
How can we tell what the interiors of planets are like?
(Advanced)
How do we know that superclusters are the largest structures in the universe?
(Advanced)
Is the Local Group expanding along with the entire Universe?
(Intermediate)
What do "homogeneity" and "isotropy" mean?
(Intermediate)
What is the largest structure in the universe?
(Intermediate)
What is the origin of spiral structure in galaxies?
(Intermediate)
Where, in relation to the entire universe, is the Milky Way located?
(Intermediate)
Why do we assume that the universe is homogeneous?
(Intermediate)
Why doesn't the ammonia and methane in Jupiter's atmosphere sink into the core?
(Advanced)
Would a planet near the galactic center have a brighter night sky?
(Intermediate)
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Can superheavy elements (such as Z=116 or 118) be formed in a supernova? Can we observe them? (Advanced)
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What what a black hole merger look like from a telescope? (Advanced)
Do galaxy mergers have a major impact on star formation rates within the galaxies? (Intermediate)
Our universe is still expanding, does that mean things in our daily life are expanding? (Intermediate)
What was the bright, smoothly moving star that I saw? (Beginner)
What happened to the Arecibo Telescope? (Beginner)
Can I buy or name a star? (Beginner)
If I were hypothetically wearing a spacesuit and sitting on one of the Voyager space probes at their current positions in space, how much light would I have? (Intermediate)
What makes certain lunar eclipses so special? (Beginner)
Why is Earth's core molten? (Intermediate)
What will happen to Earth's tides as the moon moves away from us? (Intermediate)
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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 does the position of Moonrise and Moonset change? (Intermediate)
How can I find the distance to the Sun on any given day? (Advanced)
Is the Earth at the centre of the Universe? (Intermediate)
How do you measure the distance between Earth and the Sun? (Intermediate)
How long could life on Earth survive if the Sun stopped shining? (Beginner)
What is the difference between a "star" and a "sun"? (Beginner)
At what speed does the Earth move around the Sun? (Beginner)
Why do the planets orbit the sun? (Beginner)
Why does the Earth have only one moon? (Intermediate)
Can planets collide with one another? (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)
How does the position of Moonrise and Moonset change? (Intermediate)
At what speed does the Earth move around the Sun? (Beginner)
How does the location of sunrise and sunset change throughout the year? (Advanced)
What is that ring (or rainbow) around the moon? (Beginner)
If gravity isn't a force, how does it accelerate objects? (Advanced)
Can artificial gravity be created in space? (Intermediate)
If gravity isn't a force, how does it accelerate objects? (Advanced)
How do you measure the distance between Earth and the Sun? (Intermediate)
Why do the planets orbit the sun? (Beginner)
What is the difference between a "star" and a "sun"? (Beginner)
At what speed does the Earth move around the Sun? (Beginner)
Can artificial gravity be created in space? (Intermediate)
Which planet is most similar to Earth? (Intermediate)
How do we know the Milky Way is a spiral galaxy? (Intermediate)
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)
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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