What are blue crepuscular rays?

Blue crepuscular rays are light beams that shine through holes in clouds when the sun is just rising or about to set.

Imagine you're playing with a flashlight in a dark room. When you turn it on, light comes out in straight lines, right? Now imagine there's a curtain with some holes in it, the light would come through those holes like thin beams, making patterns on the floor.

That’s kind of what happens with blue crepuscular rays. When the sun is low in the sky, like when you're getting up in the morning or going to bed at night, its light goes through gaps in clouds, just like your flashlight through a curtain. The light looks blue because it's scattered by tiny particles in the air, making those special beams stand out.

The sky often turns blue when the sun is low because of how sunlight interacts with the air. It’s similar to why the sky looks blue on a clear day, the same scattering effect, just stronger when the light has to travel farther through the atmosphere. So those beams look like long, soft blue lines in the sky, almost like the sun is shining from behind the clouds.