Hundreds Of Mysterious 'Fairy Circles' Seen From Space For First Time

The drylands of Namibia and Australia are home to some peculiar formations. Mysterious ring-like patterns of vegetation surround barren patches of soil, but no one knows why.

These so-called fairy circles have puzzled scientists for decades. Now, new research, shedding light on their global distribution, hopes to provide new insights into the formation and location of these puzzling patterns.

"There are many hypotheses regarding the formation of fairy circles, for example, they are described as a consequence of the self-organization of vegetation," Emilio Guirado, from the University of Alicante in Spain, told Newsweek.

"Social insects such as termites, which build their nests at certain distances from each other, are also hypothesized to form fairy circles. Another hypothesis focuses on toxic latex from Euphorbia, a genus of succulent plants," Guirado said.

Until recently, fairy circles had only been identified in Namibia and Australia. But Guirado and his colleagues were curious as to where else these patterns might form. "We wondered if fairy circles would exist in more places than those traditionally observed in Namibia or Australia," he said. "We set up a model based on artificial intelligence to look at hundreds of thousands of hectares from space."

It took a month before the model produced its first results, but Guirado said it was well worth the wait: "When we saw that there were hundreds of undescribed sites in areas never studied before we were very happy and excited about the find."

The team published their results on September 25 in the journal Proceedings of the National Academy of Sciences. In total, Guirado and his team identified 263 fairy circle sites in 15 different countries over three continents.

Further analysis pinpointed certain similarities between the environmental conditions at these sites, such as aridity, temperature, low soil nutrients and high sand content. However, there was also some variation between the sites, suggesting that these circles may have formed by different means in different places.

"I think that the world can be complex and that all the hypotheses of the formation of fairy circles could have a place depending on the site or the moment," Guirado said. "It is likely that all of them are valid where they have been described and that some could be combined in a few places at once. For example, our results show that the importance of termites is greater in the Namibian zone than in Australia or the Sahel zone."

More research needs to be done to confirm these theories, but Guirado hopes that his new global atlas of fairy circles will enable these more localized analyses in the future.

"We hope that the information we publish in the paper could provide scientists around the world with new areas of study that could solve new puzzles in the formation of fairy circle patterns," he said. "For example, these results could also open the door for research on how spatial patterns may be indicators of ecosystem degradation with climate change.

"I would like to emphasize that our study provides new sites with the existence of patterns similar to fairy circles, calculates the importance of multiple variables to explain their global distribution and analyzes their stability. But undoubtedly, more specialized fieldwork is required to provide more information and results on the formation of these intriguing vegetation patterns."