Our Geo Quiz usually asks you about things on the surface of the Earth. Today we’re looking up… way up…
We want to know where the atmosphere ends and outer space begins. In other words — how high the sky?
Of course, there isn’t a boundary line up there. The atmosphere just gets thinner and thinner. But there are several ways to define the beginning of outer space. NASA says you qualify as an astronaut if you go above the 50-mile mark.
At 75 miles up, the space shuttle hits what scientists call “atmospheric drag” on its return flight home. We’re looking for the altitude commonly called the Kármán line. It’s named after a Hungarian American scientist who came up with the boundary.
And it’s the point at which the atmosphere is so thin that an aircraft can’t stay aloft without going into orbit.
So how high up is the Kármán line?
It’s amazing what you can do with an old camera, a weather balloon and a little duct tape. That’s the basic kit Robert Harrison used to take some stunning photographs of Earth. His space perspective photos have even attracted the interest of experts at NASA.
The answer to today’s Geo Quiz is at the edge of geospace. The Kármán line (named after a Hungarian American scientist) is located at 100 km or 62.1 miles above sea level. It commonly refers to the boundary between the Earth’s atmosphere and outer space. Note: Technically the Earth’s atmosphere does not end at any precise altitude. The Kármán line is an international standard.