Astronomers: the moon and the Earth could be born inside a giant «doughnut»

© Sarah Stewart/UC DavisТак the artist has imagined the birth of the moon on the orbit of the young EarthAstronomers: the moon and the Earth could be born inside a giant «doughnut»© Sarah Stewart/UC Davis

. The moon could be born not in the disk of the debris of the Earth and its progenitor theis, and hot «donut hole» of hot gas, which emerged after their collision and evaporation tenth of our planet, according to a paper published in JGR: Planets.

«This idea explains the unusual features of the moon, which are impossible to reproduce using the current theory of its birth. The moon has almost the same composition as the Earth, but still a little different. We were the first to explain these differences,» said Sarah Stewart (Sarah Stuart) from the University of California, Davis (USA).

The last 30 years, it was assumed that the Moon formed as a result of collision theis, protoplanetary body, with the «germ» of the Earth. The collision resulted in the release of their rocks to space, from this material formed the Moon. This idea well explains the mass of the moon, the low iron content therein, and other properties of the companion of the Earth.

However, this clash is a significant part of the material constituting the moon was supposed to bring hypothetical Theia. In its composition it had to be different from the Earth, as differ from them most of the terrestrial planets and near-earth asteroids. But in reality, the composition of the Earth and moon are very similar, down to the same proportion of isotopes of many metals and other elements.

Four years ago Stewart and her colleagues figured out how to explain that almost 100% similarity in the composition of the moon and the Earth, suggesting the hypothesis of a «planet-Yuly». In accordance with it, the proto-Earth was spinning so quickly that she was not like a ball, and flattened «blue», which committed one turnover in just two hours while lying on her side. Clash of theis this «uloy» would lead to full mixing of their matter and the birth of the moon, identical in composition to the young Earth.

This theory, as noted by Stewart and her colleagues, there is one major drawback for the «correct» formation of the moon requires that Theia fell to the Ground at a certain angle and speed and had carefully considered the size and weight, making this scenario extremely unlikely.

All of these problems, according to astronomers, it is possible to decide if to imagine the consequences of a collision of the Earth and theis was much more dramatic than is commonly believed today. According to planetary scientists, their head-on collision could not lead to the formation of a flat disk of debris orbiting our planet, which later arose the Moon, and a giant «doughnut» of vaporized rock and metals.

«He was really huge. Its diameter was about ten times larger than Earth, and it contained approximately the same amount of matter as one-tenth of our planet. The rest of the Land, thanks to the force of the impact is turned into a liquid and remained liquid for several thousands of years,» adds Simon Lok (Simon Lock), a colleague of Stuart.

This hot donut rapidly cooled, forcing his matter to turn into liquid and «fall» to the Earth’s surface in the form of ultra-dense and ultra-fast «flaming rain». Part of this rain settled on the surface of the future moon, whose embryo emerged on the periphery of the «donut» as a result of accidental cooling and condensation of its matter.

This idea, as noted by Stuart, OK explains not only why the Moon and Earth are very similar in their composition, but why in the bowels of the companion of our planet has almost no volatiles and light elements quickly evaporate into space at a time, until the «donut» surrounded the future of the earth and the moon.

In the near future the scientists plan to test this idea, creating a more complete model of the newborn Solar system, which takes into account all the processes that could occur on the moon at the time of her life inside the «donut», and how it affected his matter.