"Evidence of this mysterious proto-planet, it seems, may have been right beneath our feet all along." by T.K. Randall via Unexplained-Mysteries Image Credit: NASA / Joe Tucciarone The findings could not only solve the mystery of the Moon's formation, but also the mystery of two large subsurface 'blobs'. While the exact circumstances that brought about the formation of the Moon have long been debated, today most scientists tend to subscribe to a theory known as the Giant Impact Hypothesis which suggests that the Moon formed from the debris created by a cataclysmic impact between the early Earth and a proto-planet named Theia approximately 4.5 billion years ago. Definitively proving that this happened, however, has long proven a challenge because nobody has been able to find any direct evidence that Theia ever actually existed. Now, though, that could be set to change thanks to a new study of two mysterious 'blobs' of material previously discovered at the bottom of the Earth's mantle