What is the hottest layer in the atmosphere?
Scientifically, temperature in the thermosphere is defined by the kinetic energy of particles. Since molecules and atoms here absorb direct solar radiation, they move faster, raising the temperature. But due to the low density, instruments detect high “temperature” while humans wouldn’t feel it. It’s important to differentiate between temperature as a measure of particle motion and the sensation of heat.
If you’re visualizing Earth’s atmosphere in layers, think of it like an onion: troposphere, stratosphere, mesosphere, thermosphere, and exosphere. Among these, the thermosphere is the hottest. Interestingly, despite being extremely hot in terms of molecular energy, if you were in it, you wouldn’t “burn” because there aren’t enough particles to transfer heat to your skin. It’s a strange paradox—high temperature, low heat.
People often think the hottest part must be closer to Earth, like the troposphere, where we experience weather. But the truth is, the thermosphere’s direct exposure to the Sun’s radiation makes it the hottest. Aurora borealis and aurora australis also occur in the lower thermosphere, caused by charged particles colliding with gases. This adds to its scientific importance, not just its extreme temperature.
The hottest layer in Earth’s atmosphere is the thermosphere. Temperatures here can soar up to 2,000°C or even higher. However, humans wouldn’t feel this heat directly because the air molecules are so sparse that there’s little transfer of thermal energy. Satellites orbit within this layer, and the International Space Station also lies within its bounds. The high temperature results mainly from absorption of solar radiation, especially extreme ultraviolet and X-rays.
The hottest layer is the thermosphere. It is very high. The sun’s energy makes the air very hot. The temperature can be 1,500 degrees Celsius or more. It is strange because it is so far from the earth. But this is the answer I learned in my studies.