Aniya, our planes fly in the lowest layer of the atmosphere, closest to Earth. On Earth, it feels like air doesn’t weight very much, but there’s actually a lot of pressure pressing down on us at all times! But as you get higher and higher into the air, air pressure decreases, and that can be very dangerous for us to breathe. There’s less oxygen, so we would run out of air fast. That’s why airplane cabins are “pressurized,” they make it so that we can breathe that high up. It’s important that if something goes wrong and the plane starts to lose pressure, the pilots can drop oxygen masks and people will have air to breathe until they get to safety! So it is important to constantly monitor the conditions and properties of the atmosphere in order to fly the plane there and be safe.

Pilots are human beings, like you, which means that they breathe the atmosphere, also just as you do. Knowing what is in the atmosphere and what the atmosphere is doing is thus essential for their informed survival, just as it is for yours.

Also, their airplanes are flying in the atmosphere, too, which means that the properties of the atmosphere, including density, wind, temperature, and everything else, have a huge effect on how and whether their planes can fly.