* No clear boundary: There's no distinct line marking the end of Earth's atmosphere and the beginning of space.
* Different definitions: Different organizations have different definitions:
* 100 kilometers (62 miles): This is the internationally recognized Kármán line, often used as the boundary for space travel.
* 80 kilometers (50 miles): The U.S. Air Force uses this definition for pilots to be considered astronauts.
* Atmospheric layers: Earth's atmosphere extends for hundreds of kilometers, becoming thinner and thinner.
So, while 62 miles is commonly used as a starting point for "space," it's more accurate to say that space begins gradually, not at a specific distance.
