Light echo

Ok, so imagine you're standing in a big room with a bunch of walls and mirrors. You have a flashlight and you shine it on one of the walls. But, because there are mirrors all around, the light bounces off and starts to reflect all over the place.

Now, imagine the flashlight is a star and the room is space. Sometimes, stars go BOOM and explode. When this happens, the light from the explosion shoots out in all directions.

But, there might be some nearby clouds of gas and dust that the light gets trapped in, like the mirrors in our room. The light reflects off the gas and dust and creates an "echo" that we can see. This is called a light echo.

We can use telescopes to study these light echoes and learn more about the explosion that the light is echoing from. It's like listening to an echo of someone's voice and trying to guess what they originally said!