Where does Earth end and outer space begin?

When mountaineers climb Mount Everest, they routinely carry oxygen cylinders, devices that allow them to breathe freely at high altitudes. This is necessary because the closer you get to the edge of the Earth’s atmosphere, the less oxygen there is available compared to the plentiful amounts found at sea level.

This is just one example of how variable Earth’s atmosphere is and showcases the elemental makeup of its layers, from the troposphere, near the sea level, to the exosphere, in its outermost regions. Where each layer ends and begins is defined by four key traits, according to the National Weather Service: temperature change, chemical composition, density and the movement of the gases within it.

Leave a Comment