Before the Earth became the world we know it, there was a formation known as the ‘proto-Earth’. Scientists have discovered, for the first time, traces of this previous form. The clues have survived for some 4.5 billion years, making this an unprecedented discovery. Specifically, it involves an almost imperceptible change in the potassium isotope ratio in ancient rocks from Greenland, Canada, and volcanic deposits in Hawaii.
“This is perhaps the first direct evidence that we have preserved the materials of the proto-Earth”
Going into detail, a recent study led by MIT scientists and published in Nature Geoscience could answer many long-standing scientific questions regarding the formation of the Earth. The international team of researchers responsible for the discovery compares it to removing a single grain of sand from a bucket. “This is perhaps the first direct evidence that we have preserved the materials of the proto-Earth,” says geochemist Nicole Nie of the Massachusetts Institute of Technology (MIT). From what we can see, this represents a major advance in research toward understanding how the Earth and any other planet with Earth-like characteristics formed.
It was assumed that this massive event had destroyed everything on Earth, but recent discoveries suggest that this isn’t entirely true
As it was understood, after that massive explosion from the meteorite known as Theia, which melted everything on Earth and gave way to new creations (including the proximity of the moon), it was assumed that this massive event had destroyed everything on Earth, but recent discoveries suggest that this isn’t entirely true. What this breakthrough suggests is that some fragments of the “before” managed to withstand fire and time. And they’ve been here, beneath our feet, for billions of years. “We’re seeing a fragment of a very old Earth, even before the massive impact,” says Nicole Nie.
What was found in this discovery is that the key lies in the isotopes of potassium, a common but complex chemical element when it comes to identifying origins. Nie and his colleagues were looking for a deficiency in the isotope potassium-40. The fact is that potassium-40 is unstable and rare, but its presence (or absence) can tell stories from millions of years ago. “In that work, we discovered that different meteorites have different potassium isotopic signatures, and that means that potassium can be used as a tracer of the Earth’s building blocks,” the research scientists say.
The conclusions suggest that the best answer is that these rocks are remnants from the dawn of Earth’s history
The fact is that, thanks to detailed analysis of ancient rock samples from Greenland, Canada, and Hawaii, researchers discovered a unique potassium signature, never seen before. This deficiency cannot be explained by modern geological processes or by meteorite bombardment after the Great Impact. The team’s simulations show that this anomaly only makes sense if it comes from material that predates Theia. Therefore, the conclusions suggest that the best answer is that these rocks are remnants from the dawn of Earth’s history, from before the well-known meteorite, hence the importance of this discovery.
This research is very important because it involves the discovery of remnants of an Earth that no longer exists, or so we thought. The fact that the signal was found both on the Canadian Shield and in the Pacific islands suggests that these primitive fragments are not a local phenomenon. And let’s keep in mind that the most likely explanation for this anomaly is its proto-Terrestrial origin, but there’s still no absolute certainty. These rocks or fragments may be distributed throughout the Earth’s surface, hidden beneath layers and layers, so this may only be a small window into the past.
