Origin of the Moon
The most widely accepted current theory for the Origin of the Moon is that the proto-Earth was struck by another planet and that this “Giant Impact” provided a debris disk from which the Moon-forming material condensed and accreted. However, there are difficulties in reconciling this with the dynamical requirements of computer simulations of the Giant Impact.
There is growing evidence indicating that the Moon is the Earth’s isotopic twin, therefore from an isotopic perspective the material that formed the Moon appears to have been derived from the Earth. Vanadium is a particularly attractive element to use to address this problem since it is refractory, moderately incompatible and can exist in multiple valence states.