How Does Neil deGrasse Tyson Explains Why Stars Twinkle Work?

Stars twinkle because the light from them travels through Earth’s atmosphere, which acts like a wobbly glass.

Imagine you're looking at a candle through a rippling lake, the flame flickers and changes shape as the water moves. That's what happens with stars: their light bounces around in the air above us, making them look like they’re blinking or dancing.

The atmosphere is made of layers that move and shift, kind of like a giant, invisible blanket. When starlight passes through these moving layers, it bends, just like when you stick your arm in a glass of water and it looks bent. Sometimes the light gets focused more, making the star seem brighter; sometimes it spreads out, making it look dimmer.

Stars are far away, so even small wobbles in the air can make them twinkle. But the Moon doesn’t twinkle because it's much closer, its light travels through less shifting air before it reaches us, like a flame seen from across a room instead of through a lake.

So next time you see stars twinkling, picture a candle flickering through water, that’s what they're doing!