Outer space

Outer space is everything that's outside of Earth's sky. It's like a super-duper big, dark room that goes on forever! It's mostly empty, but it's not totally empty.

There are tiny bits of stuff floating around, like dust and gas. Think of it like a giant, mostly empty swimming pool, but instead of water, it's filled with darkness and tiny specks. It's so empty that it's called a vacuum, which means there's almost no air at all!

Long, long ago, people wondered what was beyond the sky. But it wasn't until much later, in the 1900s, that we really started exploring. First, we sent up balloons, then rockets! In 1961, a brave person named Yuri Gagarin became the first human to travel into space. Since then, we've sent robots to visit all the planets in our solar system, and even landed on the Moon!

Space is amazing because it's where all the stars, planets, and galaxies live! Our own Sun is a star, and Earth is a planet. There are billions and billions of other stars and planets out there. It's also where we get our sunlight from. Scientists study space to learn how everything works, like how stars are born and how planets form. It helps us understand our own home, Earth, even better.

You might wonder where space actually starts. It's not like a fence you can see! Scientists have a special line called the Kármán line, which is about 62 miles (100 kilometers) above the Earth.

If you go higher than that, you're officially in outer space! It's like the height of a very, very tall skyscraper, but way, way higher. So, even though it's mostly empty, there's a special place where our sky ends and space begins.