Where is the atmosphere thickest

Most meteors burn up in this atmospheric layer. Sounding rockets and rocket-powered aircraft can reach the mesosphere. In this layer, temperatures increase with altitude due to the very low density of molecules found here. It is both cloud- and water vapor-free. The aurora borealis and aurora australis are sometimes seen here. The International Space Station orbits in the thermosphere. It gives an extra push on its tail which helps it move faster. It also has the ozone layer , which absorbs harmful radiation from the sun.

This includes UV rays. But in the south pole, there is a hole and if it enlarges could cause issues. Actually, this layer also protects the Earth from large meteoroids. The friction within this layer causes meteors to burn up. The thickest layer in the atmosphere is the thermosphere starting at about 80 km going upwards. This is where the UV radiation from the sun turns to heat causing the air to be very hot. It can reach temperatures up to degrees Celsius or more. Actually, the thermosphere has 2 layers of its own called the ionosphere and the exosphere.

The ionosphere and magnetosphere have significant overlap between them. The ionosphere is just the inner layer of the magnetosphere. In fact, this is where the sun flows with spectacular light shows for the Aurora Borealis or Northern Lights. The exosphere is the uppermost layer of the thermosphere. It starts at about km. But there are heavier molecules such as nitrogen, oxygen, and carbon dioxide closer to the bottom of the exosphere. The atmosphere also includes water vapor.

There are also many small particles - solids and liquids - "floating" in the atmosphere. These particles, which scientists call "aerosols", include dust, spores and pollen, salt from sea spray, volcanic ash, smoke, and more.

The atmosphere grows thinner less dense and lower in pressure as one moves upward from Earth's surface. It gradually gives way to the vacuum of outer space. There is no precise "top" of the atmosphere. Air becomes so thin at altitudes between and km miles up that for many purposes that range of heights can be considered the boundary between the atmosphere and space.

There are several different regions or layers in Earth's atmosphere. Each has characteristic temperatures, pressures, and phenomena. We live in the troposphere , the lowest layer, where most clouds are found and almost all weather occurs. Some jet aircraft fly in the next higher layer, the stratosphere , which contains the jet streams and the ozone layer.