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.
Particles escape out of the exosphere into deep space. The lower boundary of the exosphere, where it interacts with the thermosphere is called the thermopause. It starts at an altitude of about 250-500 km, but its height depends on the amount of solar activity.