Fairy circles are mysterious patterns of bare soil surrounded by vegetation that appear in arid regions of the world. They are circular patches of land that are surrounded by a ring of vegetation. They can range from a few meters to several tens of meters in diameter, and they often form in regular hexagonal or triangular patterns. They have been observed especially in Namibia and Australia, but a new study has used artificial intelligence to detect similar patterns in hundreds of other locations across 15 countries on three continents.
The round discs of barren dirt, much like the mysterious crop circles that appear out of nowhere—sometimes overnight–and the “Nazca Lines” in Peru, have been an object of wonderment and study, but still there are no definitive answers.
The fairy circles’ peculiar origins have intrigued scientists for decades — and now we learn that they may be far more widespread than once thought.
Some of the most popular hypotheses to explain them include the activity of termites, the growth of plants, the formation of gas bubbles, and the intervention of aliens.
A new study has used artificial intelligence to identify vegetation patterns resembling fairy circles in hundreds of new locations across 15 countries on three continents. This could help scientists understand fairy circles and their formation on a global scale.
For the new survey, published Monday in the journal Proceedings of the National Academy of Sciences, the researchers analyzed datasets containing high-resolution satellite images of drylands, or arid ecosystems with scant rainfall, from around the world. The search for patterns resembling fairy circles used a neural network — a type of AI that processes information in a manner similar to that of a brain.
“The use of artificial intelligence-based models on satellite imagery is the first time it has been done on a large scale to detect fairy-circle like patterns,” said lead study author Dr. Emilio Guirado, a data scientist with the Multidisciplinary Institute for Environmental Studies at the University of Alicante in Spain, in an email.
The researchers determined that fairy circle-like patterns were most likely to occur in very dry, sandy soils that were high-alkaline and low in nitrogen. The scientists also found the fairy circle-like patterns helped stabilize ecosystems, increasing an area’s resistance to disturbances such as floods or extreme drought.
With the aid of artificial intelligence (AI) found that they are likely the result of natural self-organization processes. The AI model was able to reproduce the spatial patterns and size distributions of fairy circles by simulating the interactions between vegetation, water, and soil. The study suggests that fairy circles are an emergent phenomenon that arises from the competition for scarce resources in harsh environments.
This conclusion however, may not apply to all the fairy circles studied. Dr. Fiona Walsh, who as part of an international team has investigated fairy circles in the Australian outback, said, “Pattern distribution in Australia appears to be congruent with some of what we previously reported,” but further suggested that Australia’s fairy circles are inextricably linked to termite activity. Their team’s research, conducted in close collaboration with indigenous peoples, determined that in Western Australia and in the Northern Territory, termites are intrinsic to the functioning of fairy circles, called “linyji” in the Manyjilyjarra language, and “mingkirri” in the Warlpiri language, she told CNN in an email.
“Aboriginal people illustrated these patterns at least since the 1980s and said they knew of them for generations, probably millennia earlier,” Walsh said.
Despite the intensive study with the aid of the latest technology, many questions about fairy circles have yet to be answered, and the authors of the new study are optimistic that their global atlas will shed new light on this phenomenon. For now, study of the fairy circle phenomenon remains a work in progress.
“We hope that the information we publish in the paper can provide scientists around the world with new areas of study that will solve new puzzles in the formation of fairy-circle patterns,” Guirado said.