People think these three-billion-year-old spheres are proof ancient aliens existed on Earth

Nearly perfectly-formed spheres that have been found in South Africa and date back some three billion years are considered natural wonders among many.

For others, they're proof that alien life has visited our planet.

The objects, called Klerksdorp Spheres, are formed completely naturally on our planet according to scientists.

But that's still not enough to convince many doubters.

Find out more about the mysterious objects in the video above.