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Astronomy
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Galaxy Rotation Curves
Grade Level
Astronomy
AST.232 Galaxy Rotation Curves
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Why can radio measurements of hydrogen gas be useful for studying galaxy rotation curves?
A
They measure the temperature of Earth's atmosphere only.
B
They show that galaxies do not contain gas.
C
They replace the need to compare observed and predicted speeds.
D
They can trace orbital speeds beyond the brightest visible stars.
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