Nasa / Space

Geek Trivia: What is the only man-made border consistently visible from space?

What is the only man-made political border consistently visible from space? Our Trivia Geek provides the answer.

Thanks in no small part to modern technology and paranoia, the border between India and Pakistan is visible every night from Earth orbit. In an effort to curb illegal border crossings, India erected in 2003 an unbroken, overlapping series of floodlights along the entire length of its shared border with Pakistan. This border is distinctly visible to the naked eye from orbit, both for its scale and its amber hue.

Twitter-savvy astronaut Ron Garan (@astro_ron) snapped a picture of the illuminated India-Pakistan border from the International Space Station on Aug. 17, 2011. He took a follow-up shot on Aug. 21 which shows -- despite competing nighttime illumination from Islamabad and New Delhi -- the India-Pakistan border is distinctly visible from space at night.

Now, the India-Pakistan border is a mere 1,800 miles, well short of even the most conservative length estimates of the Great Wall of China. Whether a string of lights proves more effective at controlling a border than a series of clay fortifications remains to be seen, but India's barricade has one distinct advantage over China's famous Wall -- it's shiny enough to be indisputably seen from outer space.

That's not just a definitively dazzling demarcation; it's a fascinatingly fortified fixture of Geek Trivia.


Jay Garmon has a vast and terrifying knowledge of all things obscure, obtuse, and irrelevant. One day, he hopes to write science fiction, but for now he'll settle for something stranger -- amusing and abusing IT pros. Read his full profile. You can a...

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I would have to quibble with the description of the India-Pakistan border as being the only one consistently visible from space. What about North Korea's borders with South Korea and China? Its neighbors are both awash with light at night with NK being an almost oceanic dark void between them. And how about the border between Haiti and the Dominican Republic, visible by day from orbit because Haiti forests have been pretty much decimated for firewood and its neighbor's forests are mostly intact. And the India-Pakistan border is not visible by day, so, so much for consistency, there. There's three more.


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The part of China that borders North Korea is very rural and lighting in that region is very sparse, and what is there is fairly far from the border itself. You can't make out that border at all. And Haiti might be clearing their forests out, but it's not noticeable from space. Trees and grass look an awful lot alike from that high up. I can't even tell for sure what is forest and what isn't, in this photo taken from the ISS: Also, consistency doesn't mean the same thing as "always". It is consistent, in that it's always visible on the same schedule. You are absolutely right about the border of North and South Korea, though. The DMZ is lit up almost as brightly as the Indo-Pakistan border, and is certainly visible every night from the ISS and other satellites:

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