In case one of you persons doesn't understand the complexity of xenophobia, here is a nice, and clear explanation: The complexity of xenophobia, is simple the felt opinion toward foreigners, or unknown persons.
The exosphere is the uppermost region of Earth's atmosphere as it gradually fades into the vacuum of space. Air in the exosphere is extremely thin - in many ways it is almost the same as the airless void of outer space.
The atmosphere is comprised of layers based on temperature. These layers are the troposphere, stratosphere, mesosphere and thermosphere. A further region at about 500 km above the Earth's surface is called the exosphere.