The Short Answer: What is the thermosphere? The thermosphere is a layer of Earth’s atmosphere. The thermosphere is located above the mesosphere and below the exosphere.

The heat that won't keep you warm

The thermosphere lies between the exosphere and the mesosphere. “Thermo” means heat, and the temperature in this layer can reach up to 4,500 degrees Fahrenheit. If you were to hang out in the thermosphere, though, you would be very cold because there aren’t enough gas molecules to transfer the heat to you. This also means there aren’t enough molecules for sound waves to travel through.

This layer of Earth’s atmosphere is about 319 miles (513 kilometers) thick. That’s much thicker than the inner layers of the atmosphere, but not nearly as thick as the exosphere.

The thermosphere is home to the International Space Station as it orbits Earth. This is also where you’ll find low Earth orbit satellites. There’s a lot going on in the thermosphere!