I know our problems down here on earth are so very huge that it seems nobody has the enthusiasm left over to care about what’s going on it orbit or on the moon or even on Mars, but take a gander for just a moment, won’t you, at this awesome freaking photograph. (If you click on it, you’ll get a mind-blowing 1.8 MB enlargement to peruse at length.) It was taken by one of the crew members aboard the International Space Station who was looking out the window when the space shuttle Atlantis streaked by underneath, heading for a landing at the Kennedy Space Center in Florida.
This is what photographers call a night shot. The face of the earth is in shadow, so the guy with the camera took a very long exposure, maybe ten seconds, maybe thirty or more, to get enough light to fall through his camera lens so he could record this moment.
The length of the exposure is the reason the earth looks a little blurry. The space station is hustling along at about twenty thousand miles per hour, so it moved far enough in ten seconds (or whatever) to make it impossible to get a clear shot of the cloudcover. But the long exposure made it possible to record Atlantis’ re-entry as a long, fiery streak which, now that I think of it, might have been there even if they had taken a shorter exposure. The streak is ionized gas, a visible trail of the enormous amount of energy the shuttle sheds by crashing into the atmosphere. It’s hitting the atmosphere so hard that the gasses that make up the air are not merely set on fire by the friction, their electrons have been excited to the point that they’re emitting visible radiation. This is the kind of fire that alien invaders will use to roast us like ants when they finally arrive to harvest the earth on their journey toward total galactic domination. Gunpowder and bullets are sticks and stones compared to setting the atmosphere on fire at the atomic level.
Air isn’t something you normally think of as a solid object but, at the speed the shuttle is moving, it is. You can see the boundary of the atmosphere in the photograph as a thin, green line that astronauts call “airglow.”
The sun (or the moon, not sure) is illuminating it from behind, so you get to see it here as a shell around the planet. * It’s about sixty miles thick, which seems like a lot until you learn that the breathable stuff is a layer barely a mile and a half thick. That’s why airplanes have to power dive and those comical-looking plastic masks drop out of the ceiling if a window blows out. The rest of what is considered atmosphere is just dead weight holding the breathable stuff against the surface of the planet, and – here’s the part that should interest you – it’s slowly diffusing into space. The breathable stuff has to be replenished by the activity of the plants and animals here on the surface, and that’s why rock stars, tree huggers and biologists keep yapping about carbon emissions. The carbon they’re talking about is, basically, aerial shit. We’re shitting into the breathable stuff. Plants and animals are not made to breathe shit.
If I seem to have wandered from the topic, I humbly submit that you are mistaken. If you’ll just look at this photo, you can see why it’s important to explore other worlds, or just to go into orbit where we can look back at our own home planet. Even if you don’t know about the ions and the carbon and gas diffusion, you can see them in action in this photo. It’s photographs like this, and other ways of gathering information, that give us a source of data to work out the puzzle of how the universe works.
Also, it’s cool. Really cool.
*I’ve learned since I posted this drivel that airglow is not just the light of the sun or the moon being diffused through the atmosphere. The air around our planet actually glows.