The Moon Didn't Form the Way We Think!

Presently, the widely accepted theory about the formation process of the Moon is a giant impact between the early Earth and a celestial body the size of Mars, that threw out enough material in orbit that accreted in time to form our only natural satellite.

However this hypothesis is not accepted by all the scientific community, since no data was ever presented about the size of the asteroid that supposedly hit the proto-Earth or about the size of our planet at the time, so no one can say for sure if enough material was propelled in orbit to allow the formation of the Moon.

Alex Halliday of the University of Oxford and his colleagues claim to have evidence that our satellite did not form the way we think. They started from the hypothesis that if the Moon formed after a Mars-sized object struck Earth, it should still contain rock from the impacting body, in fact, it should be composed mostly of this rock.

But it doesn't. The scientists studied the ratios of light to heavy isotopes of various elements in rock from the Earth, Moon and meteorites, and found mostly matching results for everything except for the Earth and the Moon.

More precisely, the samples gathered from the Moon and the Earth contained large amounts of heavy forms of silicon and iron, so the isotopic ratios of the two celestial bodies were almost identical, with no trace of a foreign object that supposedly caused the gigantic impact.

The conclusion of the study is that the old theory must be revised and it seems that a recently proposed, modified impact theory, by Kaveh Pahlevan and Dave Stevenson of the California Institute of Technology, Pasadena, would be more accurate.

This theory states that there was an impact, but this created a hot cloud of rock vapor instead of solid matter, that mixed together while it was cooling, thus eliminating any isotopes coming from the impacting body, coming from another region of space.