Lightning bolts? Nope. Fractal Fog.

By Tom Yulsman | October 1, 2013 5:11 pm

Astronaut Karen L. Nyberg shot this photo on Sept. 27 from her perch aboard the International Space Station. (Photograph: Karen L. Nyberg/NASA)

When I first spotted this striking image in Karen L. Nyberg’s Twitter feed from the International Space Station, the word “LIGHTNING” burst across my brain.

I knew it actually was not, because the caption said plainly that what I was looking at was fog filling the river valleys of Ohio and West Virginia. Even so, the resemblance is uncanny. And the image itself is a terrific example of Earth art. Let’s call it “fractal fog.”

Just as an aside, I wanted to provide a satellite image showing the same phenomenon. But I learned to my dismay that the federal government, including NASA, has largely disappeared from the Web due to the government shut down. I’m guessing this is unprecedented.

In any case, rivers can form fractal patterns — meaning they are self-similar across different scales. I recently posted some of my own photos illustrating fractal patterns in the rivulets and sediments left behind after a creek near where I live flooded and then subsided. Now, with this image, we can see fractals repeating themselves at much larger scales, thanks to the bright white fog that fills the drainages and thereby stands out so starkly against the dark, vegetated surrounding landscape.

And what about that fog?  It’s classic valley fog — a not uncommon phenomenon in the autumn, when moisture in the atmosphere can still be relatively high but temperatures at night can cool dramatically. With that cooling during lengthening autumn nights, colder air is denser than warmer air above and tends to flow downhill into river valleys. With enough cooling, the dew point is reached, and water vapor condenses into fog. Meanwhile, the downward sinking of the air tends to confine the fog to the valleys.

Lastly, a note about the image: From the looks of it, Karen Nyberg did minimal processing before posting it to Twitter. I brought it into Aperture, my photo management application, and increased both the overall and mid contrast. I also increased definition, or micro-contrast. These changes helped overcome some of loss of detail that was notable in the original. They also enhanced the fractal patterns.

  • Neuroskeptic

    That’s awesome. I guess it resembles lightning because the physical processes involved in forming valleys and lighting-tracks are similar (water / electricity finds a ‘path of least resistance’?)

    • Buddy199

      “In physical cosmology, fractal cosmology is a set of minority cosmological theories which state that the distribution of matter in the Universe, or the structure of the universe itself, is a fractal across a wide range of scales. More generally, it relates to the usage or appearance of fractals in the study of the universe and matter. A central issue in this field is the fractal dimension of the Universe or of matter distribution within it, when measured at very large or very small scales.

      Since 1986, however, quite a large number of different cosmological theories exhibiting fractal properties have been proposed. And while Linde’s theory shows fractality at scales likely larger than the observable universe, theories like Causal dynamical triangulation and Quantum Einstein gravity are fractal at the opposite extreme, in the realm of the ultra-small near the Planck scale. These recent theories of quantum gravity describe a fractal structure for spacetime itself, and suggest that the dimensionality of space evolves with time.”

      “Fractal patterns spotted in the quantum realm”:

      Fractal patterns are apparent in animal behavior, including human, especially when observing a large number of individuals acting as a group. On the individual level, my personal hunch, NS, is that the aggregate psychological phenomenon we call “consciousness”, in its many manifestations, also has a fractal basis.

      • Tom Yulsman

        Thank you for this!

        • Buddy199

          My pleasure, you have a great blog. I enjoy taking a break to read it every day.

    • shirleydarling88

      associate degree hour! Seriously i do not recognize why additional folks
      haven’t tried this, I work 2 shifts, a pair of hours within the day and a
      pair of within the evening…And whats impressive is Im engaging from home
      therefore i buy longer with my youngsters. Heres wherever I

  • Jules Ruis

    For more information about fractals, see:



ImaGeo is a visual blog focusing on the intersection of imagery, imagination and Earth. It focuses on spectacular visuals related to the science of our planet, with an emphasis (although not an exclusive one) on the unfolding Anthropocene Epoch.

About Tom Yulsman

Tom Yulsman is Director of the Center for Environmental Journalism and a Professor of Journalism at the University of Colorado, Boulder. He also continues to work as a science and environmental journalist with more than 30 years of experience producing content for major publications. His work has appeared in the New York Times, Washington Post, Audubon, Climate Central, Columbia Journalism Review, Discover, Nieman Reports, and many other publications. He has held a variety of editorial positions over the years, including a stint as editor-in-chief of Earth magazine. Yulsman has written one book: Origins: the Quest for Our Cosmic Roots, published by the Institute of Physics in 2003.


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