The Earth literally broke the Moon’s heart when the two worlds once got too close, says a scientist. Both worlds formed from the same cloud of gas and dust in the early days of the solar system. But the blob forming the moon was ripped apart in a close encounter with Earth.

Iron from the centre of the Moon was torn out and scattered over our own planet, Peter Noerdlinger, of Saint Mary’s University in Halifax, Canada, told astronomers in Seattle.

His new proposal explains why the Earth has an iron core at its centre but its natural satellite does not.

Previous theories have suggested that the Moon formed from material ejected when Earth was struck by another planet. But Noerdlinger said such a collision would have to be “implausibly gentle” because otherwise it would have messed up the Earth’s orbit.

His calculations of the Moon’s brush with Earth show that once the iron from its core was pulled out, the remains collected to form the Moon as it is today. He claims there is evidence that the Earth acquired a veneer of iron after it formed, New Scientist magazine reports.

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