Space is closer than you might think

Space always seems so far away and much of it actually is. But space is actually quite close to where we are all sitting right now. The Kármán line, the commonly accepted boundary between the Earth’s atmosphere and space, is only 62 miles above sea level.

The line was named after Theodore von Kármán, (1881-1963) a Hungarian-American engineer and physicist who was active primarily in the fields of aeronautics and astronautics. He first calculated that around this altitude the Earth’s atmosphere becomes too thin for aeronautical purposes (because any vehicle at this altitude would have to travel faster than orbital velocity in order to derive sufficient aerodynamic lift from the atmosphere to support itself). Also, there is an abrupt increase in atmospheric temperature and interaction with solar radiation.

A distance of 62 miles can covered by a car on the interstate in less than an hour. Stable Earth orbits are achievable at only 100 miles above the Earth, with the ISS and Space Shuttles usually orbiting at a height of ~200 miles. To show how small a distance that really is, I made the following image…the orange line in the upper left represents 200 miles away from the surface.

Pretty crazy.

• Earth
• space