Curious Minute answer
What phenomenon causes a star to appear to twinkle when seen from Earth's surface?
The answer
Light bending through Earth's atmosphere
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Why it's right
Stars appear to twinkle because their light passes through layers of Earth's atmosphere with varying temperatures and densities, which bend and refract the light in constantly shifting ways. This effect, called astronomical scintillation, is why stars twinkle but planets — which appear as slightly larger discs — generally don't.
How readers answered
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Sources: NASA