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.
Although some experts consider the thermosphere to be the uppermost layer of our atmosphere, others consider the exosphere to be the actual final frontier of Earth's gaseous envelope. As you might imagine, the air in the exosphere is very, very, very thin, making this layer even more space-like than the thermosphere. In fact, air in the exosphere is constantly - though very gradually - leaking out of Earth's atmosphere into outer space.