Mysterious 'fairy circles' have started appearing all over the world

Mysterious patches known as 'fairy circles' have been leaving scientists scratching their heads for over 50 years, spawning several theories as they randomly popped up in certain parts of the world.

However, this week, scientists have announced a major new development in their long journey to understanding fairy circles - they've actually been popping up all over the world.

In short, these puzzling circles are a lot more common than we first thought.

The study found fairy circles were located in the likes of Sahel, Western Sahara, the Horn of Africa, Madagascar, southwest Asia and central Australia.

“We discovered fairy circle locations in many other places that we didn’t know existed before, because most of the work on this topic has been carried out in just two countries, Namibia and Australia,” said Fernando Maestre, an ecologist at the University of Alicante in Spain and an author of the study.

“Analyzing their effects on the functioning of ecosystems and discovering the environmental factors that determine their distribution is essential to better understand the causes of the formation of these vegetation patterns and their ecological importance,” study co-author Emilio Guirado added.

But what causes them to be there in the first place?

Well, experts believe that the presence of certain soil and climate factors - such as an average rainfall of less than 200 mm/year, and low nitrogen levels - did seem to match up to areas where fairy circles were found.

That being said, there still doesn't seem to be a concrete answer, with multiple theories having been tossed around since fairy circles were first discovered.

For instance, one theory is that grass growing in hotter climates ends up battling it out for water, meaning that as some grow, the others that die leave circular gaps in the vegetation.

Meanwhile, others have attempted to link the presence of fairy circles to droughts.

But until then, it looks like these strange circles will remain a mystery, as they have for half a century.