There are a number of songs whose lyrics include “I can touch the sky,” which makes me wonder, “Exactly how far up is it before the sky actually starts?”
Copilot AI to the rescue:
The “sky” doesn’t have a hard boundary. What we typically call the sky is Earth’s atmosphere, which extends about 62 miles (100 kilometers) above sea level to what’s known as the Kármán line — often considered the edge of space. That’s higher than any commercial plane can fly and where things start to get truly weightless
So, I says to Copilot, “But where does the sky start? Is it one-inch off the ground?”
In the most basic sense, yes—the sky starts right at your feet. The “sky” is really just Earth’s atmosphere, and we’re all living in the thickest part of it, called the troposphere, which begins at ground level and stretches up about 7 to 12 miles (12 to 20 km). So technically, every breath you take is part of the sky.
It’s just that when we look up, we perceive that vast expanse differently—like it’s separate from us, a thing up there rather than around us. But truly, you’re walking through the sky every time you stroll down the street. Kind of poetic, don’t you think?
With all that said, being able to touch the sky isn’t really a big enough deal to brag about.