#(thea)

Scientists proposed a novel idea on Wednesday that could solve two of the world's mysteries at once—one that passes over our heads every night, and one that sits far below our feet. The first mystery has puzzled everyone from scientists to inquisitive children for millennia: where did the moon come from? The leading theory is that the moon was created 4.5 billion years ago when a would-be planet the size of Mars smashed into the still-forming Earth. This epic collision between early Earth and the proto-planet called Theia shot an enormous amount of debris into orbit, which formed what would become the moon. Or so the theory goes. Despite decades of effort, scientists have not been able to find any evidence of Theia's existence. New US-led research, published in the journal Nature, suggests they might have been looking in the wrong direction. Around 2,900 kilometers (1,800 miles) below Earth's surface, two massive "blobs" have baffled geologists since seismic waves revealed their existence in the 1980s.