Earth’s Atmosphere

Earth’s atmosphere consists of 78% Nitrogen, 21% Oxygen, and one percent Argon. You may have thought, it was mainly composed oxygen since that’s what we breathe but actually most of earth’s atmosphere consist of Nitrogen.

There’s enough Oxygen at 21% of the atmosphere to be enough for us to breathe and live normally and then there’s one percent Argon and there are also trace amounts of water vapor, Carbon dioxide, and other gases. Dust particles and chemicals from earth.

1. The majority of Earth’s atmosphere is made up of
2. All life and weather occurs in the


Next Lesson: Structure of Atoms

The transcript is provided for your convenience
Anything you release into the air is going to the atmosphere so even though it’s  not going to make up a certain percentage of the atmosphere, if you don’t release too much, those would be trace amounts and that composition may vary a little bit from area to area at least while you’re close to the earth. As you get further away from the earth, the atmosphere becomes thinner that means there are going to be less particles, there’s going to be less molecules or atoms of Nitrogen, less of Oxygen, less of Argon, less of anything. The further out you go, the more spaced out those atoms are going to be and so the further you get away, the less you’re going to be able to breathe as well.

If you go about three kilometers above sea level it becomes hard for you to breathe because the particles are spaced out more and so all you may still have 20% of the atmosphere made up of Oxygen where you’re at. If it’s all spaced out then you’re not going to be able to breathe than as much Oxygen as you need to live and function normally so the further you get away, the thinner the atmosphere gets, the fewer particles are going to be in the air because they’re spaced out, so far apart and this happens until gradually the atmosphere just fades into space and that’s it. There’s space. There’s not a distinct line between the atmosphere and space because there’s still little atmospheric particles and drifting right along the edge so there’s not like a cutting dry line for where it goes.

The atmosphere extends about 10,000 kilometers towards space and then it kind of fizzles out and there’s just space after that. Let’s look at the different layers of the atmosphere and I’m going to start at the bottom where we’re closer to Earth’s surface. Down here, we have Earth and this layer is the Troposphere. The Troposphere is where all life happens so any living things are going to be here in the Troposphere and where most weather occurs.

You may see some clouds in the layer above but most weather occurs down here in the Troposphere  so that’s your bottom layer and here, if we were to look at a sampling of particles, you would just have particles everywhere because there is so much Nitrogen, Oxygen, Argon and other particles in the Troposphere where all life happens, where you have particles of the atmosphere most densely packed. Troposphere is where our most weather happens and where all life happens. Any living things are going to be functioning down here unless they’re sent out possibly in a space ship which is a very rare occurrence, most people aren’t going to do that. You could live out here in a space ship but you have to be protected and you have to have an atmospheric condition inside your ship that matches close to what you have down here in the Troposphere. Okay?

Moving up, the next layer of our atmosphere is the Stratosphere and the Stratosphere has the Ozone layer in it so the Ozone layer helps shield us from some of the Sun’s harmful radioactive rays and this is where we find it. It’s not going to be in the Troposphere and the Stratosphere is where you’ll find the Ozone layer and again, let’s look at the sampling of the particles. Here you would still have a lot but not as many as down here. It still wouldn’t be easy to breathe up here. It would be very difficult if not impossible maybe right on the border you may find areas like where mountain peaks, jag up into the Stratosphere and you may be able to breathe if you’re being very still but it’s going to be labored breathing because you’re not going to have near enough  particles to breathe up here.

Next, we have the Mesosphere. The Mesosphere is the coldest layer and the atmosphere behaves in a very interesting way so where going up and everything’s getting a little warmer and then it gets colder so the Mesosphere is the coldest layer and it is where meteors or shooting stars will burn up before they hit the Earth. It works out well for us because the Mesosphere helps burn all those up before they’re going to hit Earth and if we look to the sampling of particles here, you would not have very many. They’d be very spaced out.

Next we’ve got the Thermosphere. The Thermosphere is the hottest layer so remember I said the atmosphere behaves in a very interesting way. We are going and the temperature’s got a little warmer and then it got really cold so it’s the coldest layer, very cold temperatures and then it gets really hot to about 1700 degrees Celsius in the Thermosphere so very very hot temperatures but this is also where satellites orbit, they are built to withstand those kinds of heat conditions so satellites such as the International Space Station are orbiting in the Thermosphere still within Earth’s atmosphere. Fill with the particles here, you would see very few particles, very spaced out.

Keep in mind that you’re going to have more particles when you’re closer to Earth and fewer particles as you get out. The last layer is the Exosphere which is really just the area after the Thermosphere where the particles start to fizzle out so if you were to look there, you might not even see any particles because they’re so spaced out that if you just look for a sampling, you wouldn’t catch them. They’d be very spaced out  and so it fizzles out into space so from here, you are falling into space. The atmosphere is split into these five layers.

The Troposphere is where all human life and plant life, animal life, all life occurs and where most weather occurs. The Stratosphere has the Ozone Layer, maybe some high flying clouds. The Mesosphere is the coldest layer where meteors burn up. The Thermosphere is the hottest layer where satellites orbit and Exosphere is what’s after  the Thermosphere is the atmosphere is gradually fading into space and as you go from Earth out towards space the air gets thinner. There are fewer particles and the atmosphere acts kind of like a blanket of air around the Earth. You keep it insolated so it’s thicker as its closer to Earth and slowly gets thinner as it fades towards space. Keep in mind that, that means since we have Oxygen to breathe down here the further you get out, the less you’re going to be able to breathe as well. Our atmosphere is there
to protect us, it has the Oxygen we need to breathe and other gases that plants need as well so if we didn’t have our atmosphere, we wouldn’t be able to have life on our planet. It’s a very important aspect to Earth but it’s there to protect us, it’s thicker and has more particles closer to Earth and then gradually fades out and gets thinner until it hits space.

Next Lesson: Structure of Atoms