At what altitude does our atmosphere end and outer space begin?
There are a few recognized “strata” to our atmosphere: Troposphere, Stratosphere, Mesosphere and Ionosphere. I wasn’t able to find an agreed-upon definition for where outer space begins, though a number of sources seem to claim that outer space begins at 100 km (62 miles). There is a great diagram at http://csep10.phys.utk.edu/…/atmosphere.html if you’d like to see the thickness of the various layers of our atmosphere. What it essentially shows it that the Troposphere extends approx. 14 k, above the surface, then there is a 4 k, thick Tropopause. The Stratosphere tops out at about 50 km above the surface, then another 40 km of Mesosphere, followed by about another 300 km of Ionosphere. Different sources may show different measurement, but ultimately it depends on what you consider outer space.
