Have you ever seen a photo of an astronaut floating in space? The Sun is shining so brightly behind them that it almost hurts to look at. But right next to that bright Sun, the sky is totally black. Not dark blue like night on Earth. Black, like someone turned off all the lights.
An astronaut named Tim Peake said the same thing surprised him. He said space wasn't just dark, it was the blackest black he had ever seen. So here's the big question: if the Sun is so bright, why doesn't it light up the space around it?
The answer is something you can actually test at home. Light needs something to bump into before we can see it glowing. Think about a flashlight in a dusty room. You can see the beam because the light bounces off all the tiny dust bits floating in the air. Now imagine that same flashlight in a room with absolutely nothing in the air at all, not even dust. You wouldn't see a beam. You'd only see light where it lands, like on a wall.
That's exactly what happens in space. Our sky on Earth is full of air, tiny invisible bits called gas, and sunlight bounces off all of it. That bouncing light spreads out and fills the whole sky, which is why our daytime sky glows blue instead of looking black. But space has no air at all.
It's almost completely empty. So when sunlight travels through space, it doesn't bounce off anything and doesn't light anything up. It just zooms straight ahead in an invisible line until it crashes into something solid, like a planet, a moon, or an astronaut's helmet.
This is also why the Moon's sky looks black even in the daytime. The Moon barely has any air, so there's nothing there to catch the sunlight and spread it around like a glowing sky.
Astronauts who walked on the Moon could look up in broad daylight and see both bright sunshine and a coal-black sky full of stars, all at the same time. You could never see that on Earth, because our air is always glowing during the day.
So space isn't black because it's far from the Sun or because the Sun isn't powerful enough. Space is black because there's nothing there for sunlight to bounce off, so the light just stays invisible until it hits something.
The brightest thing in our sky and the darkest black we know sit right next to each other, separated by nothing but empty space. So next time you look at a starry night, think about this: that blackness isn't empty at all, it's full of sunlight zooming through it. We just can't see it unless it lands on something, like a planet, a moon, or maybe even you.