A new study states that moon may have formed when a primordial planet with a chemical composition strikingly similar to that of Earth collided with our planet.
The study, which was published in the Nature journal, states that a violent collision between Earth and a similar planet, Theia, created Moon.
Hagai Perets, an assistant professor in the physics department of the Technion, Israel, and one of the members of the study, said, “Study of lunar rocks has shown that the moon and Earth are almost identical in their composition. This is one of the major challenges for this really beautiful giant impact hypothesis.”
The researchers looked at a phenomenon in the early history of the solar system, which suggests that both Earth and the moon gathered additional material after the main impact between Earth and Theia, and that Earth collected more of this debris and dust. According to the researchers, this new material contained a lot of Tungsten, but relatively little of this was of a lighter isotope known as Tungsten-182. Taking these two observations together, one would expect that Earth would have less Tungsten-182 than the moon.
The researchers analyzed rocks from the moon and Earth, and found that the moon has a slightly higher proportion of Tungsten-182. This supports the idea that the mass of material created by the impact, which later formed the moon, must have mixed together thoroughly before the moon coalesced and cooled. The researchers believe that this would explain both the overall similarities in isotopic fingerprints and the slight differences in Tungsten-182.
“Theia and Earth were formed in the same region, and have therefore collected similar material. These similar living environments also led them eventually to collide; and the material ejected mostly from Theia, ultimately formed the Moon,” added Dr. Alessandra Mastrobuono-Battisti, researcher at the University La Sapienza, and one of the members of the study.