Bosnian stone mystery: Natural or human-made?

An archaeologist has discovered a large stone sphere in a Bosnian forest, and it's causing quite a stir.

An archaeologist has discovered a large stone sphere in a Bosnian forest, and it's causing quite a stir.

The giant ball of rock is up to five feet in diameter and it contains a lot of iron. 

Semir Osmanagic, the archaeologist, believes it could have been made by humans 1,500 years ago.

But Atlas Obscura points out that Osmanagic has made big claims before that didn't always pan out - like in 2005, when he said he found ancient pyramids linked by underground tunnels in Bosnia. His claims that they were made by a 12,000-year-old civilization where disputed by his peers, who said they dated back to the Middle Ages. 

It isn't the first time stone spheres have turned up in Bosnia, but this is the biggest one so far. And it does bear an uncanny resemblance to the Death Star.

Osmanagic apparently claimed at one point that the spheres might have been alien-made. But these days he's a bit more practical.

Geologists have another theory - that the spheres were formed naturally, the result of an act of nature (called concretion) over many years. 

"A huge stone sphere discovered in a forest near the town of Zavidovici, in Bosnia and Herzegovina, led Bosnian archaeologists to speculate that it may be the largest and oldest sphere of its kind in Europe carved by human hands, Wednesday:"