Are You Closer to the Sea or to Outer Space?
What are you closer to right now—the nearest ocean or the edge of space? Reddit user @Many-Excitement3246 created a map that answers this question in a way I haven’t seen before.
Red areas on the map are closer to the sea. Violet regions are closer to outer space. The dividing line is the Kármán line at roughly 100 kilometers (62 miles) above the surface . Why that height? The Fédération Aéronautique Internationale chose it because aircraft wings can’t generate lift anymore when the air gets that thin.
Look at that narrow red band following the coasts. Earth is 12,742 kilometers (7,918 miles) across. Space? Just 100 kilometers up. That’s less than 1% of the planet’s diameter.
| Diameter | Kilometers | Miles |
| Average Diameter | 12,742 | 7,918 |
| Equatorial Diameter | 12,756 | 7,926 |
| Polar Diameter | 12,714 | 7,900 |
You’ve got the Kármán line at 100 kilometers. But the air we actually breathe? That comes from way closer to the ground. The troposphere contains 85-90% of all atmospheric mass. It only extends 8 to 20 kilometers up depending on where you are. Almost all the atmosphere (99% of it) is packed into the first 30 kilometers (19 miles) above the surface.
What actually keeps us alive is thinner than this map shows. Make a version marking where 90% of the air sits, and that coastal band would practically vanish. We’re living under a film of breathable air so thin it wouldn’t even show up on most globes.
Mountain climbers know this firsthand. Summit of Everest? That’s 8.8 kilometers. Get up there and only one-third of the atmosphere is below you. Jets cruise between 9 and 12 kilometers, and they have to pump pressurized air into cabins because your lungs can’t pull in enough oxygen at that height.
It should be noted, the atmosphere doesn’t just stop at 100 kilometers. It thins out over hundreds and thousands of kilometers until it becomes vacuum. The outermost traces stretch up to about 10,000 kilometers.
