MIT Scientists Discover 4.5-Billion-Year-Old Proto-Earth Vestiges

(MENAFN) In a groundbreaking discovery, scientists from the Massachusetts Institute of Technology (MIT), working with international partners, have identified what may be preserved traces of “proto-Earth” — the planet’s primitive predecessor dating back 4.5 billion years.

The study, published Tuesday in Nature Geoscience and reported by ScienceDaily, offers a rare look into the ancient materials that existed before the colossal planetary collision believed to have formed modern Earth.

“This is maybe the first direct evidence that we've preserved the proto Earth materials,” said Nicole Nie, the Paul M. Cook Career Development Assistant Professor of Earth and Planetary Sciences at MIT.

The research team uncovered an unusual isotopic fingerprint in deep mantle rock samples collected from Greenland, Canada, and Hawaii. These samples show a notable deficiency in the radioactive isotope potassium-40 compared to most present-day terrestrial rocks.

“We see a piece of the very ancient Earth, even before the giant impact. This is amazing because we would expect this very early signature to be slowly erased through Earth's evolution,” she said.

The isotopic anomaly points to the possibility that these rocks still contain minuscule fragments of Earth’s original building blocks — remnants that have withstood billions of years of geologic transformation.

For decades, scientists have attempted to reconstruct Earth's initial makeup by comparing it to various types of meteorites. However, this new research suggests those models are incomplete.

“Scientists have been trying to understand Earth's original chemical composition by combining the compositions of different groups of meteorites. But our study shows that the current meteorite inventory is not complete, and there is much more to learn about where our planet came from,” Nie explained.

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