The most commonly accepted theory for the creation of the Earth is that it was formed from an aggregate of rocky meteors and asteroids that came together and built up over time. But new research indicates that far from being a stony conglomerate, the proto-Earth may have been a huge ball of churning, warm, wet mud.

The core accretion model for the creation of the Solar System says that the terrestrial worlds, like Earth, were formed out of materials similar to today's stony meteors. This would have made the first core of the planet a dry, stony mass that would grow larger as more debris was drawn in by the growing planetoid. Eventually, the stony core would be joined by iron/nickel meteors, the mass would grow, heat up, and form into a huge ball of molten iron and silica slag.

Curtin University planetary scientist Phil Bland and Planetary Science Institute Senior Scientist Bryan Travis have other ideas. They contend that the original debris didn't undergo the thermal alterations that created modern meteors. Instead, the huge ring of dust and debris that preceded the Solar System condensed slowly into lumps of porous, igneous clasts, similar to certain kinds of volcanic rock, and other lumps of fine-grained dust.

The pores of these conglomerates would have been stuffed with ice, which remained trapped inside as the meteors rained down on the proto-Earth. Over time, radioactive elements would have heated up the ball in the same way they keep the Earth's core molten today. But instead of melting the rock straight away, the radioactive decay melted the ice and started convection currents that mixed the water and the debris to form a ball of warm, ever churning mud.

The basis for this conclusion was Travis' Mars and Asteroids Global Hydrology Numerical Model (MAGHNUM) computer simulation, which he used to model the distribution of rock grain sizes and flow of mud in carbonaceous chondrite asteroids. What he found was that many of these early asteroids brought water and organic material to the early planets instead of just consolidated rock.

According to the Planetary Science Institute, these new findings could help to provide not only a better understanding of the evolution of the Solar System, but also aid in the search for habitable exoplanets beyond it.

The research was published in Science Advances.

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