Retroreflector

A retroreflector is like a special mirror that can reflect light directly back to where it came from. Imagine you have a flashlight and you want to shine it on something far away so you can see it better. The flashlight bounces off the thing and comes back to your eyes so you can see it. A retroreflector works the same way, but with light from something far away bouncing back to the source.

Think of a retroreflector like a cat's eyes. You know how the eyes of a cat shine in the dark because of their reflective surface? Retroreflectors work in a similar way. When light shines on them, they reflect it directly back where it came from, even if it's a long way away.

Scientists love to use retroreflectors because they're really good at bouncing back laser beams. They can be placed on the moon, for example, to reflect beams from Earth with incredible accuracy. That way, we can measure the distance between the two objects with great precision.

So, in short, a retroreflector is like a mirror that reflects light back where it came from, and scientists use them a lot to measure distances in space.