whenever you look up in the sky what do you see at first glance there might not seem to be much above you perhaps some clouds the sun and a few birds however the most complex aspects of the sky above you cannot be seen the very air itself that surrounds planet earth is comprised of a group of layers that combine to form the atmosphere earth's atmosphere is a blanket of gases that surround the planet the atmosphere is made up of five layers each of these layers is unique because of the differences in temperature and particle composition
the five layers of earth's atmosphere starting closest to the ground are the troposphere stratosphere mesosphere thermosphere and exosphere the troposphere is the first layer of earth's atmosphere it starts on the planet's surface and stretches up to an average of seven miles in the air this layer is the densest meaning it has more particles and heavier gases than the other levels the majority of earth's weather occurs within the troposphere this layer is also the warmest at the bottom as it is closer to the heat that the earth is absorbing from the sun as you go farther
up into the troposphere the temperature drops the next layer that begins at the top of the troposphere is the stratosphere the stratosphere stretches for about 30 miles outward into space this layer is the maximum height at which jets can fly the stratosphere also contains the ozone layer this layer of molecules absorbs much of the sun's powerful ultraviolet rays and protects life on earth all of these absorbed rays make the ozone layer quite warm just above the stratosphere is the mesosphere this layer is about 40 miles above earth's surface here meteors from space burn up and
are destroyed ironically the mesosphere is the coldest layer of the atmosphere the cold molecules scrape the incoming meteors which cause friction and eventually fire the mesosphere is so cold because it is far away from the absorbed heat of earth but still quite far from the sun temperatures can be as low as negative 190 degrees fahrenheit miles up from earth's surface is the thermosphere this layer of the atmosphere is where space shuttles and satellites orbit the planet the temperature of the thermosphere is incredibly hot because of energy coming directly from the sun at this level temperatures
can reach up to 2 700 degrees fahrenheit at this height the air is quite thin and there are very few molecules the final level of the atmosphere is called the exosphere it extends about 6 200 miles into space in the exosphere atoms and molecules from earth escape into outer space and completely leave the planet's atmosphere temperatures can vary widely here from very cold to very hot depending on location although the five layers of earth's atmosphere have gone through temperature and thickness changes over time they have remained in place for millions of years and continue to
protect life on this planet
