London: In a new study, scientists have proposed a fresh idea in the long-running debate about how the Moon was formed.
The fact that is certain is that some sort of impact from another body freed material from the young Earth and the resulting debris coalesced into today`s Moon, but the exact details of the impactor`s size and speed have since remained debatable.
In a new study, researchers have suggested that the crash happened with a much larger, faster body than previously thought, the BBC reported.
Such theories need to line up with what we know about the Moon, about the violent processes that set off the creation of moons, and what computer simulations show about the more sedate gravitational “gathering-up” that finishes the job.
In recent years, scientists` best guess for how the Moon formed has been that a relatively slowly moving, Mars-sized body called Theia crashed into the very young Earth.
That would have heated both of them up and released a vast cloud of molten material, much of which cooled and clumped together to give rise to the Moon.
This would suggest that the Moon is made up of material from both the early Earth and from Theia, which should be somewhat different from one another.
What complicates this story is a number of observations of “isotopic compositions” - the ratios of naturally-occurring variants of some atoms - taken from the Earth and from lunar samples.
While the Moon has an iron core like Earth, it does not have the same fraction of iron - and computer models supporting the Theia impact idea show just the same thing.
However, the ratio of the Earth`s and the Moon`s oxygen isotopes is nearly identical, and not all scientists agree on how that may have come about.
The study will be published online in Icarus.