The Namibian desert’s “fairy circles” are one of nature’s greatest mysteries. From above, it almost looks like the ground has suffered a bad case of chicken pox. But up close, you can see the circles for what they really are: patches of barren land surrounded by tufts of grass.
Fairy circles cover swathes of the most inhospitable parts of Namibia’s desert, and for centuries they’ve mystified the local bushmen, the Himba, who believed the circles were either footprints of the gods or the work of an underground, fire-breathing dragon.
Other theories have also been floated over the years by conspiracy theorists, scientists and everyone in between, with the phenomenon being blamed on everything from giants and underground gas; to termites, radiation and aliens.
But for all these musings, an unshakeable explanation has yet to be found.
Until now, that is.
Thanks to an unexpected discovery in -- of all places -- Australia, thousands of miles away from Namibia’s desert, scientists believe they may have found a plausible answer: the grass, they say, surrounding the circles are “self-organizing,” creating the polka dot pattern in the process.
A study published this week in the Proceedings of the National Academy of Sciences reveals that fairy circles -- long believed to be unique to Namibia -- have been discovered in the Western Australian outback.
“We couldn’t believe it,” ecologist and study co-author Stephan Getzin told the Smithsonian of the stunning find. “The Namibia fairy circles are supposed to be the only ones in the world.”
Like the Namibian fairy circles, the Australian versions have also cropped up in arid areas. They look very similar, too: circular dirt patches surrounded by vegetation arranged, as Getzin put it, in a regular hexagonal pattern “like a honeycomb spacing in bees.”
On average, the Australian circles are large enough to almost “fit a minivan,” the Smithsonian says.
Getzin, a scientist at the Helmholtz Center for Environmental Research (UFZ) in Leipzig, Germany, has previously suggested that the self-organization of plants in response to a shortage of water may be the natural cause behind Namibia’s fairy circles.
“The amount of water available at the transition between desert and grassland isn't enough for continuous vegetation cover. So the individual plants compete for the precious water and therefore organize themselves in this characteristic grass carpet with holes in it,” explains a recent UFZ new release of the process.
In other words: when water is scarce, the liquid gets pulled in all directions by the plants, leaving patches of ground so dry that nothing can grow there.
This “self-organization” idea had been skewered by skeptics who argued that if it were indeed true, fairy circles should appear in places other than Namibia where conditions are similar.
The discovery Down Under has thus greatly strengthened this hypothesis, said Getzin, who was first alerted to the Australian fairy circles in 2014. Since then, he and a team of researchers have used fieldwork, remote sensing, spatial pattern analysis, and mathematical modeling to test their theory.
“In Namibia, the sandy soils of the fairy circles are much more permeable and precipitation can drain away with ease,” said Getzin in the release. “The details of this mechanism are different to that in Australia. But it produces the same vegetation pattern because both systems of gaps are triggered by the same instability.”
The Australian discovery also suggests that fairy circles might exist elsewhere in the world. “I suspect there are more fairy circle patterns -- it’s a matter of searching,” Getzin told the Smithsonian.
Still, though compelling, this theory remains just a theory for now.
More studies and experiments will need to be conducted to confirm the hypothesis. There are also some experts who doubt the Australian fairy circles are fairy circles at all.
There are others though who say they're encouraged by these developments.
Nichole Barger, an ecosystem ecologist at the University of Colorado, Boulder, told The New York Times that the new research finally “moves us closer toward a unifying theory of fairy circle formation.”
Use Google Earth below to explore Namibia's fairy circles, and learn more about the latest study at UFZ's website here.