How High is Space? Astronomy Facts

[!Jon Snow!]

Look up, there’s space. Astronomically speaking, it’s right there, just outside a thin layer of atmosphere. But how far away is it? How high is space?

 

[Nova]

As far as space goes, there is no end. Because space is relatively nothing, its infinite.

 

[Drakkith]

The Kármán line, at an altitude of 100 km, is typically used as the start of space and the end of the atmosphere, but not always.

http://en.wikipedia.org/wiki/Kármán_line

 

[BobG]

Not always because the Karman line considers the impact the atmosphere has on aerodynamic flight, but ignores the impact the atmosphere has on orbital flight. You'd actually have to be a bit higher than 100 km to achieve at least one entire orbit.

But at least 100 km is a nice round number.

And it is the most common definition, in spite of its shortcomings.