How does the James Webb Space Telescope see back in time?

The James Webb Space Telescope can see faraway stars and galaxies that are so far away, it takes their light a long time to reach us.

Imagine you're looking at a firefly on the other side of a big lake. The firefly blinks once, but by the time that blink reaches your eyes, it might be seconds later. Now imagine that firefly is billions of light-years away. That means when we see it, we’re seeing it as it was long ago, not as it is now.

The James Webb Space Telescope works like a super-powered time machine for light. Light from faraway objects travels through space, sometimes taking millions or even billions of years to get here. When the telescope catches that old light, it shows us what those distant stars and galaxies looked like back then, just like seeing a blink from a firefly on the other side of a lake.

The telescope has special tools that help it catch even the faintest light, kind of like how you might use a magnifying glass to see tiny details on a leaf. These tools let scientists look at very old, very faraway things and understand how the universe used to be.