How Did Former 'Fireball' Earth Become Habitable? Researchers Explain Mystery

A new theory that Yale and Caltech researchers explained how Earth evolved from a flaming, carbon-clouded ball of rocks to a planet capable of supporting life.

The notion is based on "strange" rocks that reacted with saltwater in precisely the proper manner to prod living matter into being during Earth's early years.

Researchers published the findings of "A wet heterogeneous mantle creates a habitable world in the Hadean" in the journal Nature. Yoshinori Miyazaki, a Stanback Postdoctoral Fellow at Caltech, is the first author. The other author is Jun Korenaga, a Yale professor of Earth and planetary sciences.

Earth's Former Condition Explained

About 4.6 billion years ago, Earth was born from the Sun's protoplanetary disk.

Universe Today said the planet started off as a molten spheroid with sweltering temperatures.

Earth cooled over time, and a firm crust developed. The atmosphere eventually cooled, and life became possible.

Researchers point out that Earth's atmosphere was dense with carbon, which had to be eliminated for the temperature to drop and the Earth to become livable.

Hadean eon refers to Earth's first 500 million years. Hades, the Greek God of the Underworld, inspired the name. Hades is also a colloquial term for Hell.

The Hadean eon gets its name from the Hadean eon. Earth remained blazing hot even after it began to cool and harden. The amount of carbon in the atmosphere was 100,000 times more than it is now.

The early Earth resembled Venus, which has a thick atmosphere that retains heat and maintains high temperatures.

Earth's surface temperature would have surpassed 200 degrees Celsius (400ºF) during the Hadean.

The planet had to clean a lot of carbon from its atmosphere before it could cool.

However, piecing together events on the very young Earth has proven difficult for scientists. For one reason, there is a scarcity of geological evidence.

Korenaga said per WIONews: "This period is the most enigmatic time in Earth history."

The Hadean was not only mysterious but also lively. During those 600 million years, the globe underwent several modifications.

However, geological evidence suggests that by the middle of the Hadean, Earth's surface environment was comparable to today's.

The authors note in their article that it's unclear under what conditions a hostile surface environment may become livable.

How Did Earth Become Livable?

The carbon cycle appears to have stabilized temperatures to the point that life could thrive comfortably by the end of the eon, about 4 billion years ago.

One idea is that carbon from the atmosphere dissolved into the seas and solidified into carbonates, which sank and became lodged in the mantle's currents.

To test if they could make the idea work, Miyazaki and Korenaga used models from fluid mechanics, heat transfer, and atmospheric physics. The findings indicate that a specific type of rock got exposed to our planet's surface.

In a Science Alert report, Miyazaki explains that these rocks would have been concentrated in pyroxene, and they would have been dark greenish in hue.

More importantly, Miyazaki explained these rocks were extraordinarily magnesium-enriched, with concentrations rarely seen in modern rocks.

A quickly churning crust of wet, molten rock filled with pyroxene may account for the rapid release of all that CO2 in a stabilizing process that would take millions, not billions, of years.

All of that magnesium-rich rock would subsequently be left well beneath our feet after a cooling that gave us a regenerative crust made up of a handful of slowly moving plates.

Water-logged minerals would have swiftly dried as the crust rapidly flipped over, filling the seas to the levels people observe today.

The concept is interesting, not least because such an occurrence would have aided at the beginning of life in numerous ways.

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