00:07Dear viewers and students, today we will learn about an interesting question.
00:16The question is, why stars twinkle but planets do not twinkle?
00:22The answer is, as stars are extremely far away, so they appear as point sources of light.
00:38When their light passes through Earth's turbulent atmosphere, means layers of air with changing temperature and density.
00:54It bends randomly, which causes the stars' brightness and position to fluctuate, which produces twinkling.
01:09And planets do not twinkle because they appear larger in size than stars.
01:21Planets are much closer to Earth than stars, so they appear as extended sources, means in disk shapes rather than
01:39point sources like stars.
01:42Planets appear in the shape of disks and stars appear in point sources, means like point sources.
01:58When light from a planet passes through Earth's atmosphere, the atmospheric disturbances affect different parts of the planet's disk differently.
02:14These variations cancel each other out, and brightness remains constant, means light appears steady.
02:26Hence, planets do not twinkle.
02:30So, finally, we can say that stars are point sources, so they can twinkle.
02:40But planets are extended sources, means disk shapes, so they do not twinkle.
02:51So, that was about today's question.
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