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Are aliens or UFOs real?
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Can I listen to the SETI@home radio signal?
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Can life exist on the recently discovered extrasolar planets?
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Can supernovae hinder the formation of life in galaxies?
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Could there be life in the galaxies nearest to the Milky Way?
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Do similar laws of physics throughout the Universe imply that all life must be like life on Earth?
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Do you believe in UFOs?
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Do you think it's possible to maintain life on other planets?
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Have astronomers observed any phenomena that could be produced by extraterrestrial civilizations?
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Is it worthwhile to continue the search for extraterrestrial life?
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Is there oxygen in the atmospheres of other planets?
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What do meteorites tell us about life on other planets?
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What is a Dyson Sphere?
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Where is everybody?
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Why does the SETI project search for radio signals?
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Why search for only Earth-like life on other planets?
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Would extraterrestrial civilizations know that there is life on Earth?
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Wouldn't the vast distances of space distort SETI signals into unintelligeble forms?
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Is there really a 10th planet? (Beginner)
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Do galaxies that are receding from us faster than the speed of light disappear from our observations? (Intermediate)
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Can two galaxies move away from each other faster than the speed of light? (Intermediate)
What is a graviton? (Intermediate)
Why are there high tides during a Full Moon? (Intermediate)
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Have the inner planets cleared their neighborhood? (Intermediate)
What caused the Big Bang and created the Universe? (Beginner)
If spacetime is curved, is it possible for us to look into space and see light from Earth from long ago? (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)
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Are the planes of solar systems aligned with the plane of the Galaxy? (Intermediate)
When was the last time all of the planets were aligned? (Beginner)
What color is each planet? (Intermediate)
How do you measure the distance between Earth and the Sun? (Intermediate)
What is the difference between a "star" and a "sun"? (Beginner)
What is the significance of the Tropic of Cancer, Tropic of Capricorn, Arctic Circle and Antarctic Circle? (Beginner)
How does the position of Moonrise and Moonset change? (Intermediate)
At what speed does the Earth move around the Sun? (Beginner)
Why do airplanes take longer to fly West than East? (Intermediate)
Why are the Moon and Sun sometimes orange or red? (Beginner)
What color is each planet? (Intermediate)
Are the planes of solar systems aligned with the plane of the Galaxy? (Intermediate)
How do you measure the distance between Earth and the Sun? (Intermediate)
Why is the Universe flat and not spherical? (Advanced)
When was the last time all of the planets were aligned? (Beginner)
What is the significance of the Tropic of Cancer, Tropic of Capricorn, Arctic Circle and Antarctic Circle? (Beginner)
Why do airplanes take longer to fly West than East? (Intermediate)
What is the difference between a "star" and a "sun"? (Beginner)
At what speed does the Earth move around the Sun? (Beginner)
How far is each planet from Earth? (Intermediate)
What color is each planet? (Intermediate)
How do you measure the distance between Earth and the Sun? (Intermediate)
What is the significance of the Tropic of Cancer, Tropic of Capricorn, Arctic Circle and Antarctic Circle? (Beginner)
At what speed does the Earth move around the Sun? (Beginner)
When was the last time all of the planets were aligned? (Beginner)
What is the difference between a "star" and a "sun"? (Beginner)
How far is each planet from Earth? (Intermediate)
Why do airplanes take longer to fly West than East? (Intermediate)
How does the location of sunrise and sunset change throughout the year? (Advanced)
How are light and heavy elements formed? (Advanced)
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)
How long does it take for the Sun's light to reach us? (Beginner)
What is the universe expanding into? (Intermediate)
When will Halley's Comet return? (Intermediate)
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