The question of the origin of water on Earth is important and complex, as Earth has lost all evidence of its formation because it is an active planet. In this article, we'll show you everything you need to know about the origin of water on Earth!
What is the Origin of Water on Earth?
Water on the Earth's surface is an anomalous feature compared to other studied planets. Due to the importance of water for sustaining life, the question of the origin of water on Earth is of paramount importance. The major problem in investigating this question is that Earth has lost all traces of its formation, as it is an active planet.
We have always wondered , "How was water created?" Sometimes it is thought that water arrived on Earth aboard asteroids, a product of the remnants of the alignment of the solar system. It is thought that these drops fell on Earth as a result of an incessant bombardment that took twenty million years until the seas and oceans were formed.
Modern water on Earth has existed since its very formation is unusual and barely matches, firstly, with the study of other rocky planets devoid of surface water and secondly, with the idea of a giant impact between the proto-Earth and the Mars-sized planetary embryo, which formed the Moon.
Such a catastrophic event should have evaporated any existing water, leaving the Earth dry, after this event we have two options to explain the presence of water on Earth, the water returned later, after the catastrophe, in the form of ice or asteroids rich in water or the giant impact was not big enough to evaporate all the water on Earth.
While Earth and Venus can be seen as twin sisters, their respective geological and climatic changes in the past were dramatically different, resulting in the modern atmosphere of Venus at a pressure of 92 bar heating up to 470°C, in contrast to the mild temperature and pressure of 1 bar at the Earth's surface.
However, volcanic activity and gas evolution are less pronounced on Venus than on Earth, because there is no plate movement on it, convection tempering on Venus involves very little recirculation of volatiles in the mantle.
This means that the evolution of the atmosphere of Venus is much easier to understand and form geological changes, also, due to their proximity, the Earth and Venus must have admitted the same type of material throughout their history, all these Harmonious countenances make Venus an excellent place to learn about the evolution of the terrestrial planets.
Using numerical simulations of the impacts of different types of asteroids containing varying amounts of water, the team found that water-rich asteroids colliding with Venus and releasing their water as vapor cannot explain the composition of Venus' atmosphere as it is. we know today.
This means that the asteroid material that hit Venus and thus Earth, after a giant impact, had to be dry, which prevented replenishing Earth with water using asteroids, consequently water would not It disappeared after the giant impact, which means that, most likely, it was very deep in the Earth.
This thought has deep contradictions to the habitability of ancient Earth, Venus, and Mars, since it suggests that the planets possibly built themselves up with an almost complete supply of water and squandered it over time, since Mars is much smaller, surely wasted all of its water while life evolved on Earth.
For Venus, these results shed more light on the study of aquatic oceans on the planet's surface and help limit the maximum amount of water that can be expected on Venus, this information could help future space missions to Venus.
Three scenarios are considered to explain the origin of terrestrial water :
First stage
In the first scenario, the water molecules would have been protected from solar radiation within the "dust" of the original cloud, during the formation of the Solar System, when the dust accreted to form planetoids, the water remained protected inside.
The planets then shrank as they grew, which forced water outward, a bit like a waterlogged sponge being squeezed, of gas like carbon dioxide being expelled in parallel, creating an atmosphere.
On Earth, the conditions of temperature and pressure caused the water to pass in liquid form and therefore, the oceans. They appeared, protected from the radiation of the atmosphere, the water has been able to maintain itself until today.
On Venus, the high temperature kept the water in the form of vapour: the radiation then broke up the water molecules in the upper atmosphere and finally the hydrogen was expelled from the water, today, water is almost non-existent on Venus.
second stage
The other scenario involves asteroids and comets: they come from very distant regions of the Solar System, which are precisely rich in water; however, at the beginning of the history of the solar system, impacts were very numerous because a large number of bodies continued to rotate within the protoplanetary disk in Planetary Transits ; this could bring a significant amount of water to Earth, carrying it from the confines of the Solar System.
Observations today tend to indicate that both of these scenarios played a role in explaining the current amount of liquid water on Earth.
a third scenario
In recent years, a third scenario has come to light, it seems feasible to transport water to the star, in irrefutable planetary systems, in fact, observations of exoplanets have led to the discovery of a large number of gas giants located near their star, in the area regularly set aside for terrestrial planets.
Therefore, it was necessary to imagine a hypothetical migration of planets at the beginning of the history of these planetary systems, the gas giants would have formed far from their star, as in the solar system, but then migrated towards their star due to interactions. with residual powder disc.
This is a great way to bring abundant water from the far reaches to regions closer to the stars, the process is similar to that of comets, but on a much larger scale as it involves entire planets! Assuming that the gas giants end up losing their hydrogen and helium due to the radiation of the star, they could become true planet-oceans, the presence of continents would be impossible there because the depth of the water would be from a few hundred to thousands of kilometers.
Theories of the Origin of Water on Earth
Scientists have been discussing the theory of water and how it appeared on our planet for a long time. Most experts adhere to the view that water was brought to Earth approximately 3.600 billion years ago, even during the active formation stage of the planet, when thousands of large and small asteroids and comets continuously bombarded it.
Scientists believe that some of these asteroids were quite large and contained a decent amount of water in the form of vapor, liquid or ice, now a new theory has emerged, Japanese experts suggest that almost all the water on Earth appeared here and not It was brought from space.
Geologists from the Tokyo Institute of Technology state that, at the time of Earth's creation , large layers of hydrogen were present in the Earth's structure , which entered into a chemical reaction with the oxygen present in the Earth's mantle, resulting in the formation of water on the planet in gigantic quantities.
Geologists speculate that right after the planet was formed, it was very hot and dry, in theory millions of water-rich comets and asteroids attacked the Earth many, many years ago, which further exposes why the oceans appeared after that finished the alignment of the planet.
