The atmosphere is a protective layer of gases which surrounds the Earth - it has main layers, each with their own individual characteristics.<br /> <br />If the Earth was the size of an onion our atmosphere would be only as thick as the onion’s skin - it is made up of 78% nitrogen, 21% oxygen and 1% other gases.<br /><br />It allows life to exist on Earth by protecting us from the harmful bits of the Sun’s radiation.<br /> <br />Whilst also keeping the Earth warm, through a process known as the Greenhouse Effect.<br /><br />It also contains the air we breathe and is a major part of the water cycle. <br /><br />The atmosphere is split into 4 main layers based on temperature.<br /><br />The troposphere is the lowest; starting at the Earth’s surface and extending upward to on average 10km.<br /> <br />We live in this part of the atmosphere and nearly all weather happens here. Most clouds appear in the troposphere because 99% of the atmosphere’s water is found there.<br /> <br />As you get higher in the troposphere, the temperature gets colder.<br /> <br />Next comes the stratosphere – which extends from the top of the troposphere to about 50km.<br /><br />The stratosphere contains the ozone layer, which absorbs high energy UV light converting it into heat. <br /><br />In the stratosphere, temperatures actually get warmer the higher you go. <br /><br />Above the stratosphere is the mesosphere, which extends upwards to a height of around 85km.<br /><br />Most meteors burn up in this layer. This is the coldest layer of the atmosphere and the air at this height is far too thin to breathe <br /><br />At its coldest this layer can go as low as -100° C.<br /><br />The highest part of what most consider to be the Earth’s atmosphere, is the thermosphere - which goes on to between 500km and 1000km. <br /><br />Temperatures can vary from between 500 and 2000°C or higher, although at this altitude the air is so thin that this is not the same as temperature as we experience at the surface <br /><br />The aurora, the Northern Lights and Southern Lights, occur in the thermosphere. The International Space Station also orbits in this layer<br /><br />Music credit: Meat by JCM
