History of Solar System and Earth's Formation Hidden In Meteorites

A concept image of our solar system forming. (Photo : NASA/JPL-Caltech)

The history of Earth may be hidden in objects not even from this planet. Scientists from the Carnegie Institute for Science are examining old meteorites called diogenites to uncover clues about the formation of our planet.

Terrestrial planets such as Earth eventually separate into different strati such as the mantle, crust, and the core. When this happens, a great deal of heat and energy is expended, and the process gives clues as to why a certain planet formed that way.

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"This new understanding of diogenites gives us a better picture of the earliest days of our Solar System and will help us understand the Earth's birth and infancy," one of the authors of the paper Doug Rumble from Carnegie said. "Clearly we can now see that early events in planetary formation set the stage very quickly for protracted subsequent histories."

The mantles of the Earth and moon are believed to have formed around 4.4 billion years ago, and the mantle of Mars, 4.5 billion years ago. When examining the Earth's core, scientists noticed something was off.

From the press release:

"...certain elements including osmium, iridium, ruthenium, platinum, palladium, and rhenium-known as highly siderophile elements-are segregated into the core. But studies show that mantles of the Earth, Moon and Mars contain more of these elements than they should."

To figure out more about how the Earth formed, the researchers turned to diogenites, incredibly old meteorites that come from large enough celestial bodies such as the asteroid Vesta to have undergone the same geological differentiation Earth went through.

What they found is that the siderophilic elements present in the diogenites could only occur after core formation had taken place. The process was found to have taken place in the relatively short span of 2-3 million years, and shed more light on the developmental phase that Earth went through.

Also from the press release:

"In the case of Earth, there followed crust formation, the development of an atmosphere, and plate tectonics, among other geologic processes, so the evidence for this early period is no longer preserved."