Had the Moon not collided with the Earth it's likely that it could have become a planet similar in composition to our own. This is according to a multitude of studies which are making their debut in the journal Nature.
The three studies conducted in Israel and France all come to the same conclusion: that the Moon is definitively not a chunk of the Earth, it's also not an even mix between the Earth and the object that hit us.
Instead, it appears as though the Moon is unique, and yet, extremely similar to the composition of our own planet.
Speaking on the Nature podcast, one of the paper's main authors Dr Hagai Perets explains:
"If the impactor had a different composition from the Earth, we should expect the Moon to have a different composition. They are almost identical. This is one of the major challenges for this really beautiful giant impact hypothesis,"
"What we found is that many of these impactors on a planet have very similar composition to that of the planets they impact - as similar as what we measure between the Earth and the Moon,"
It had originally been thought that the proto-Earth had been hit by an extremely light object with the resulting debris then binding together to form the Moon.
However for this to be the case, the composition of the Moon would have needed to be very different from that of our own planet.
Instead, the three papers show that in fact the Earth shares many of the same materials, including a 'veneer' of impact material when both the Earth and Moon went through a period of heavy bombardment.