The India/Pakistan border at night (NOAA imagery courtesy Ka Chun Yu)

There is a lot that can be known only by nightfall. Seen at night -- and from a distance -- the Earth can reveal new truths about itself and its occupants.

I mention that because of the image above, which is based on data captured by Suomi NPP, the Earth-observing research satellite that orbits the planet as a collaboration between NASA and NOAA. This afternoon, as part of a presentation at the Aspen Ideas Festival, Dr. Ka Chun Yu and Dr. Bob Raynolds of the Denver Museum of Nature and Science presented the image as part of a broader view of Earth seen at night -- and from space.

The image depicts the lights of India and Pakistan. It shows the areas of human concentration -- the cities and highways and other bits of infrastructure. You can tell, via the darkness, where the rural areas are. And you can tell, if you look a little more closely, where rivers are.

And if you look more closely still, you can see something else, too. Smack in the middle of the image -- vaguely echoing the lines of the river to its left -- is a spindly line of light winding down the length of the image. It's a line notable for its line-iness: Instead of the bursts of illumination that give the map its sense of organic humanity, the line threads down at a uniform width. 

That line is the International Border, the recognized geographic divide between the two countries. The line of lights is the fence built to demarcate the separation. 

Most imagery of space is notable for its transcendence: it shows one Earth and recognizes neither nations nor the disagreements between them. This one, however, is notable for the opposite. The divide between India and Pakistan here isn't overcome by more universal things. It's stark. It's bright. And it's visible from space.