There’s Another Earth Inside The Earth?
A team of Harvard scientists may have found an indication that a portion of an ancient Earth exists inside our planet’s mantle.
As presented at the Goldschmidt conference in Sacramento, California, the study suggests that the inexplicable isotope ratio from the depths of the Earth could be an “echo” of the ancient Earth that existed before the collision, which is said to have led to the formation of the Moon, around 4.5 billion years ago.
Scientists of the Harvard University led by Associate Professor Sujoy Mukhopadhyay state that only a portion of the Earth melted back then as a result of the collision, and that there still exists a part of the old Earth.
They found that the ratio of 3He to 22Ne from the surface layers of the mantle is much higher than the one of its deeper layers.
The analysis of the 129-Xenon and 130-Xenon ratio also confirms this. Material which has been rendered to the surface from the deep mantle has a lower ratio than the one which is typically located near the surface.
Since the 129-Xenon is produced by the radioactive decay of 129-Iodine, these isotopes indicate that the ancient part of mantle was created during the first 100 million years of the Earth’s genesis.
Scientists believe that this explains the differences between the isotope ratios of noble gases in different regions of the Earth.
Professor Mukhopadhyay explained, “The geochemistry indicates that there are differences between the noble gas isotope ratios in different parts of the Earth, and these need to be explained. The idea that a very disruptive collision of the Earth with another planet-sized body, the biggest event in Earth’s geological history, did not completely melt and homogenize the Earth challenges some of our notions on planet formation and the energetics of giant impacts. If the theory is proven correct, then we may be seeing echoes of the ancient Earth, from a time before the collision“.