Monday Bites: For Thy Light Is Come

Monday Bites: For Thy Light Is Come 

Credit: Public Domain, via Wikimedia Commons 

Four hundred kilometers (almost two hundred-fifty miles) high above the surface, the astronauts onboard the International Space Station (ISS) get to live through things none of us folks here can ever witness unless we go up there. 

For starters, when you're going around the world in just under ninety-three minutes, the sun rises and sets every forty-five minutes; day and night cycle sixteen times in twenty-four hours. From low-earth orbit, sunsets and sunrises take on a whole new dimension. 

After a good day's work, as you drop into the Cupola — the observation deck — to enjoy your limited leisure moments and to take a good look at your home down below, you finally see how magnificent your planet is. Though you have no doubts regarding Earth's shape, looking towards the distance, you can't help but appreciate the sharp curve cutting across the blackness of space. 

As your floating fortress passes over the terminator line — the diffuse line dividing day and night — you, for the first time, get to see how day transitions into night. The sun going down, the atmospheric layers, the troposphere spill apart like a mad painter's palette of brilliant yellows, brighter oranges, and darker reds; the stratosphere with little to no clouds appears with a shade towards the pink, and higher up, it's all blue until there aren't much gases left to scatter the sunlight and its all dark. In the moments after sunset, or sunrise for that matter, when the sun has dropped way over the horizon, the atmosphere thins out to a brilliant blue crescent, thinner than the first moon, tracing its curve against the boundless expanse of space. 

Descending into Earth's shadow, you can see the cities spread out like hundreds of golden cobwebs, interconnected as a whole, and while your folks sleep through the long night, for you, its only a matter of forty-five minutes before the sun comes up. 

What you see here is the sun coming up. The thin blue arc is the entirety of Earth's atmosphere under which life breathes, and that sparkling yellow diamond is our sun. This image was taken on September 14, 2018, onboard the ISS.