Where exactly is space? More specifically, where does it start and where does Earth's atmosphere end? There has been much debate in the scientific community about this seemingly simple question. Today, the Kármán Line recognizes that boundary—it sits at 100 kilometers (62 miles) above sea level. The line is named after Theodore von Kármán, a Hungarian-American engineer and physicist. However, any NASA test pilot or astronaut who crosses an altitude of roughly 80 kilometers (50 miles) is awarded their astronaut wings. In other words, it's basically the velvet rope you can to cross to enter the astronaut club. Sign us up.
Share the knowledge!
Key Facts In This Video
Space is defined by the point at which Earth's atmosphere ends, and the vacuum of space takes over. 00:13
Any NASA test pilot or astronaut who crosses an altitude of roughly 80 kilometers (50 miles) is awarded their astronaut wings. 00:38
The Earth's outer atmosphere, known as the exosphere, extends to an altitude of 10,000 kilometers (6,200 miles). 01:48
Wake up with the smartest email in your inbox.
Our best articles a few times a week.