Water can be described as ubiquitous, rain and snow, rivers and lakes… There are waters around us, but few people will ask “Where does the water come from?” The answer to this question is also very complicated, and I am afraid it will be traced back to the origin of the universe.
At the time of the Big Bang, protons, neutrons, and electrons were all huddled at temperatures as high as 10 billion degrees. Using these basic components, just after a few minutes, the two light elements, hydrogen and helium, begin to form. The process is called “nuclear synthesis.” The heavier elements appear later, synthesized by nuclear fusion of light elements inside the star and during the supernova explosion. As time goes by, more and more heavy elements are born in the stars, and various elements including oxygen are continuously sent into space, mixing with lighter elements.
Of course, the formation of hydrogen molecules and oxygen molecules is completely different from the formation of subsequent water. Because even if hydrogen molecules and oxygen molecules are mixed together, energy stimulation is required to turn into water. This is a very intense reaction process, and scientists have yet to find a way to safely synthesize water on Earth.
Then, where did the rivers and lakes covered by the earth come from? Scientists still don’t know the answer, but some ideas have been put forward. One theory is that about 4 billion years ago, the surface of the Earth was bombarded by millions of asteroids and comets. Looking at the dense crater on the moon’s surface, you can probably imagine what the earth was like at the time. According to the theory, these asteroids and comets that hit the Earth are not ordinary rocks, but something like a “sponge”. The water stored in it is released to the earth after hitting the surface.
Although astronomers have confirmed the existence of water in asteroids and comets, the theory has been questioned by some scientists: the amount of water in the Earth’s oceans is so large that it may not be able to provide enough water by asteroids and comets. In addition, the researchers also found that the heavy water contained in the comet of Haier Pope (that is, the water molecule consisting of one hydrogen atom, one helium atom and one oxygen atom) is much more than the Earth’s ocean, which means that it either hits the earth. Comet is very different from asteroids and comets of Haier Pope, or the common water on the earth (ie, water molecules composed of two hydrogen atoms and one oxygen atom) has another source.
And not long ago, the former conjecture may have been confirmed by astronomers. Using the Stratospheric Infrared Observatory (SOFIA), astronomers have discovered that when Vertainen’s comet reached its nearest point in December last year, the water vapor that was released into space “is very similar to seawater.”
The Vertanin Comet is a “super-active comet” that emits more water vapor into space. The researchers came to this conclusion by comparing the ratio of normal to heavy water in steam. There is a certain proportion of heavy water in the earth’s oceans and ordinary water, and the ratio of the two kinds of water on the Vertanin comet seems to be the same as that of the earth. Because the Earth’s atmosphere can cause obstacles, we can’t observe the wavelength of infrared light from the Earth. We can only use the space telescope and the stratospheric infrared observatory located in the upper atmosphere to carry out reliable observations on comets.
There is also a theory that the earth was once bombarded by heavy elements such as oxygen formed inside the sun during youth, and these oxygen elements are separated from the gas released by the earth by a process called degassing. The combination has gradually formed the ocean and atmosphere on the earth.
Another group of Japanese scientists has proposed another theory, saying that the surface may have been covered by a thick layer of hydrogen and gradually interact with the oxides in the earth’s crust, eventually forming the ocean.
A computer simulation in 2017 provided another explanation for the source of some surface waters. It was thought that water might have formed deep in the mantle and eventually came to the surface with the earthquake.
In summary, although we can’t completely determine where the water on the earth comes from, at least it should be fortunate for this result.