Paper suggests impacts blasted off parts of Earth’s starting material

It’s generally thought that the Earth was built out of asteroids called ordinary chondrites. Chondrites contain some of the most ancient minerals in the Solar System, and their composition suggests that they made up the majority of the material that collapsed to form our planet. But recent observations have shown that the composition of the Earth’s mantle doesn’t match that of ordinary chondrites, suggesting that something else is going on.
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