Karman line

The Karman line is like an imaginary "border" in space that separates Earth from outer space. It's named after a scientist called Theodore von Karman who worked on the idea of where exactly the Earth's atmosphere ends and space begins.

Think of Earth like a big ball, covered in a layer of air, called the atmosphere. The atmosphere is made up of different gases, like nitrogen and oxygen, that surround the planet's surface. But as you go higher up in the air, the atmosphere thins out and eventually fades away.

The Karman line is the point at which the atmosphere is so thin that a vehicle (like a rocket or an airplane) would need to travel at extremely high speeds in order to generate enough lift to stay in the air. This point is located approximately 100 kilometers (62 miles) above the Earth's surface.

So, to put it simply, the Karman line is the point in space where the Earth's atmosphere gets so thin that it's difficult for vehicles to stay up in the air without huge amounts of speed and energy.