The elements hydrogen and helium together comprise what percent of almost all matter in the Universe?
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83 percent
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96 percent
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98 percent
-
75 percent
Which element was discovered on the Sun before it was discovered on Earth?
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Hydrogen
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Plutonium
-
Helium
-
Uranium
When 3 celestial bodies within the same gravitational system align to form a straight line, what is it called?
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Conjunction
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Disparity
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Appulse
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Syzygy
Our planet is named Earth, from soil, or simply the world. What was the ancient Greek name for Earth?
What is a bright region in the Sun called?
Sunspot
Flare
Plage
Prominence
To astronomers anything that interferes with observing, such as smog, fog, and dust, is called what?
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SkyPollution
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LightPollution
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Pollution
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AirPollution
Olympus Mons, the highest peak on Mars, was discovered by which spacecraft?
Viking 1
Mariner 9
Voyager 2
Mars 2
How long is Earth's sidereal year?
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364.897Days
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365.87Days
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365.242Days
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365.256Days
What is the final stage in the life cycle of an average-mass star?
Neutron Star
Red Giant
Black Hole
White Dwarf
What is the name of the closest star to our Earth?
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AlphaCentauri
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Andromeda
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Sol
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Polaris