Schematic representation of the five principle layers in Earth's atmosphere. The bottom layer, the one that we all live in, is the troposphere, extending to an altitude of about 10 km (6 miles). Above this is the stratosphere, from 10 to 50 km (6 to 32 miles). Here resides the bulk of the ozone layer. Next is the mesosphere, from 50 to 90 km (32 to 56 miles). At an altitude of 100 km (62 miles) is the so-called Karman line, where space is deemed to begin. Above the mesosphere is the thermosphere, where most meteors burn up and the aurora are created, and which goes up to about 500 km (310 miles). And above the thermosphere is the outermost layer, the exosphere.