The first primitive form of the earth was created in just five million years – much faster than imagined
The first primitive form of the earth was created in just five million years – researchers have discovered much faster than previously thought.
In fact, if the entire history of the solar system was condensed in a 24-hour period, the formation of the Earth would have lasted the equivalent of 90 seconds.
Experts, on the other hand, had thought that this would have lasted 16.7-50 million years – or, in the 24-hour clock analog, about 5-15 minutes.
The Danish team shuns traditional theories that the proto-earth has formed through random collisions of ever-larger planetary bodies over tens of millions of years.
Instead, they put forward the idea that the planets were created by the relatively rapid build-up of cosmic dust.
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The primitive shape of the earth has been created in five million years – researchers have discovered much faster than previously thought. Pictured, the impression of an artist of a protoplanetary disc
“We start with dust – essentially millimeter-sized objects – that all come together, rain down on the growing body and make the planet in one go,” said paper author Martin Schiller from the University of Copenhagen.
“Not only is this implication of the rapid formation of the Earth interesting for our solar system, it is also interesting to judge how likely it is that planets form somewhere else in the Milky Way.”
The key to the new findings came from the most accurate to date measurements of the mixture of iron isotopes in different meteorites.
Dr. Schiller and colleagues found only one type of meteoric material with a composition similar to that of the earth – a type known as ‘CI chondrites’.
Dust in this type of meteorite is described by the team as the best equivalent of the bulk composition of the solar system itself – and it was dust like this, along with gas, that formed the disk of matter around the sun from which the planets were formed.
When the young earth first began to form, the iron dust it built up had a unique composition, such as due to thermal change from the sun.
After the first few hundred thousand years of the solar system, it became cold enough to allow unchanged CI dust from further into the system to enter the area where the proto-earth was built.
“This added CI substance overpressed the iron compound in the Earth’s mantle, which is only possible if most of the previous iron had already been removed from the core,” Dr. explained. Schiller.
“That’s why the core formation must have happened early.”
“If the formation of the earth was a random process where your bodies simply struck each other, you could never compare the iron composition of the earth with just one type of meteorite. You would get a mix of everything. “
The Danish team shuns traditional theories that the proto-earth has formed through random collisions of ever-larger planetary bodies over tens of millions of years. Instead, they put forward the idea that the planets were created by the relatively rapid build-up of cosmic dust. Pictured, an artist’s impression of the young earth, seen from space
“If the theory of early planetary fouling is really correct, water is probably only a by-product of the formation of a planet such as the Earth,” said paper co-author and cosmochemist of the University of Copenhagen, Martin Bizzarro.
This, he added, makes the ingredients of life as we know it more likely to be found elsewhere in the universe.
“If we understand these mechanisms in our own solar system, we can draw similar conclusions about other planetary systems in the Milky Way – including at what point and how often water is grown.”
Researchers believe that other planets in the universe can also grow rapidly through the accumulation of cosmic dust.
This means that planets outside our own solar system can be faster than they already were, which increases the chance that they will find life elsewhere in the universe.
The full findings of the study were published in the journal Science is progressing.
HOW SHAPES PLANETS?
In our current understanding, a star and its planets form a collapsing cloud of dust and gas in a larger cloud called a nebula.
As gravity material in the collapsing cloud draws closer together, the center of the cloud becomes increasingly compressed and in turn becomes hotter.
This dense, hot core becomes the core of a new star.
In the meantime, inherent movements within the collapsing cloud cause it to churn.
As the cloud becomes extraordinarily compressed, much of the cloud starts turning in the same direction.
The rotating cloud eventually becomes flat in a disk that becomes thinner as it rotates, much like a rotating lump of dough that becomes flat in the shape of a pizza.
These ‘circumstellar’ or ‘protoplanetary’ disks, as astronomers call them, are the birthplace of planets.