Hypotheses of hydrosphere formation. How did water appear on the Earth?

How and when did water appear on the Earth? Scientists are still debating on this topic, but no one has given an accurate and logically proved answer. To date, there are several assumptions about how liquid could form on the planet. Among them there are both completely absurd and logical hypotheses, but so far none of them is completely reliable.

How did water appear on the Earth? Briefly about the main hypotheses

Water plays a big role in maintaining life on the planet, because it is the main internal environment of any organism. Without water, a person can on average not last more than three days, and a loss of 15-20% of the fluid often leads to death.

How did water appear on the Earth? Hypotheses of the formation of this substance are few, and neither of them has yet received truthful evidence. Nevertheless, only they can somehow explain the formation of the hydrosphere of our planet.

The hypothesis of the cosmic origin of water

A group of researchers suggested that water appeared along with numerous falling meteorites. This happened about 4.4 billion years ago, when the planet was still in its infancy, and its surface was a dry, devastated land over which the atmosphere had not yet formed.

When asked how the water appeared on the Earth, the adherents of this hypothesis answer that the first molecules of this liquid were brought with them by meteorites. At first these molecules existed in the form of gas and accumulated, and later, when the planet began to cool, the water passed into a liquid state and formed the hydrosphere of the Earth.

Perhaps the chemical formation of water originated from primary hydrogen protons and oxygen anions, but the probability of such a reaction in the thickness of celestial bodies, which subsequently fell to Earth, is catastrophically small.

Another hypothesis, as water appeared on Earth

It was suggested by a group of researchers led by a well-known scientist V.S. Safronov. The essence of his assumption is the terrestrial origin of water, which was formed in the bowels of the planet.

Under the influence of numerous falls of meteorites, at that time our incandescent planet began to form a large number of volcanoes, from which magma escaped. Together with it "water vapor" was allocated to the surface, which caused the formation of the Earth's hydrosphere.

Despite the fact that the theory has laid the foundation for the terrestrial origin of water, it can not answer many questions. For example, how did the rocks in the lithosphere melt so much to cause the formation of many volcanoes? And how did water vapor form? First, scientists assumed that at that time there was groundwater, which through the vents of volcanoes, together with the magma, burst out in the gaseous state.

This theory of steam formation was refuted by Peter Perro, a naturalist of the 17th century. He proved that groundwater was formed due to precipitation, and for this, the presence of an atmosphere is necessary. 4.4 billion years ago, the atmosphere did not exist.

And the latest theory

So how did the water appear on the Earth? Another hypothesis was able to approach the problem of formation of the planet's hydrosphere on the other hand. Like the previous assumption of VS. Safronovy and his co-authors, this hypothesis is repelled from the terrestrial origin of the water.

The difference is that according to the researchers, the water molecules were formed together with the protoplanetary disk of the Earth, i.e. At the time of the formation of the planet itself. The source of water molecules was deuterium and oxygen.

Deuterium is a conventional hydrogen with one neutron in the nucleus. This heavy isotope was found in samples of ancient basalts found in the Arctic on Baffin Island Land (1985). These rocks are formed from particles of protoplanetary dust that have not been affected during the formation of the planet. According to the researchers, the chemical nature of deuterium would not allow the isotope to form outside the planet.

That's how water appeared on Earth in the opinion of these scientists. If their data are correct, about 20% of the modern world ocean formed during the formation of the protoplanetary disk. Today, researchers are looking for a way to prove that much of the world's ocean has formed from "protoplanetary" water, as well as atmospheric water vapor and groundwater.