The Moon and Theia

William sent in the link https://www.nationalgeographic.com/premium/article/moon-forming-collision-theia-left-chunks-deep-within-earth-mantle … 4.5 billion years ago another planet, the size of Mars, crashed into the Earth – leading to the formation of the Moon. It has been theorised that the Moon is formed out of the debris from a collision – but that has yet to be proved. It has been accepted as a consensus soley because it is the best of what is on offer as an explanation for our companion. Scientists, in a new study, now claim they have found pieces of Theia at the bottom of the  Earth’s Mantle. They were discovered by seismic waves travelling through the interior of Earth following an earthquake. As the waves pass through materials of different densities they change velocity or direction. They say by this method they can map the inside of the Earth. There are two enormous blobs in the lower Mantle that shift in densisty and composition from their surroundings. Seismic waves slow when passing through these regions. This is one of those theories impossible to validate. I wonder if it will become consensus.