The Next Layer of Air

Walking up to the top of Mt. Everest, one would find that the air is not only thin, but that it's technically too thin for most humans to breathe in. Good that it's not another 500 meters higher, otherwise it would really not be possible without oxygen.

At the same time, air pressure there is three times as high as on the Martian surface, meaning that it's still relatively thick for a rocky planet.

Twice as high as Mt. Everest, however, is where the real fun begins. For that's about where what we know as the troposphere ends. Above it, there is no life, no weather (wind, snow or rain), no moisture, no clouds - only very cold, very thin air. Welcome to the stratosphere.

If you book a "near space" flight, this is where it will take you.

But if you think that this no longer constitutes an atmosphere, then you are highly mistaken. Compared to space, this is even a "thick" atmosphere - of course all such matters being relative. While the Stratosphere reaches from about 18km (at the equator) to 50km, this is not even the layer of air in which space dust/particles burn up as what we know as "falling stars". That's the next layer, the Mesosphere (meaning "middle orb"), where everything from outer space either burns up because of the friction the air here causes or is slowed down enough that it can usually make it to the earth's surface as a meteor. This is where the space shuttle blew apart on re-entry.

No, the Stratosphere is so thick that it even stops light from reaching earth's surface. Well, not much light, but enough to make it safe for us to run around outside. Right in the middle of the Stratosphere is the ozone layer, which stops a good bit of the high-powered ultraviolet light from the sun, turning it into low-powered infrared light - what we usually just call heat. Or at least warmth.

And surprise! At the top of the Stratosphere, it's warmer than on top of Mt. Everest!

And warmer than many a cold winter's day here in the temperate zones on the surface. But don't worry, water would not freeze or even turn to liquid up there because the air is quite thin (again, relatively speaking in relationship to the earth's surface), and because there's no water in the air anyway.

So what we find is really a world between worlds - absolutely nothing going on. The first satellites (and space junk) are flying by at about 100 Kilometers higher, at 10km/s by the way. Ten Kilometers per Second! 36,000 Kilometers per Hour! But if those satellites have to stay at that low orbit for very long, they will slow down quickly, because of atmospheric drag, and soon fall back out of orbit, burning up / breaking apart in the Mesosphere before traversing through the Strato- and Troposphere on their way to the surface.

If we put a floating object in the atmosphere, it would not move. Relative to the earth's surface it would stay in one spot, except for gradual drift resulting from the fact that the earth rotates. Other than that, the object would not even need to be tethered to the earth's surface. That means that an object put above Timbuktu would stay above Timbuktu, needing only occasional adjustments because the earth spins.

Nothing moving, nothing around, no space junk, acceptable temperatures, thin air. The latter point can be solved only with a space suit or a pressurized capsule. Is it any wonder that I think the stratosphere should be our first goal, long before we try populating space?