There is a view that in the early days of the birth of the earth, the atmosphere and hydrosphere were inseparable, and the water at that time was a mixture of gaseous (steam) and primitive atmosphere. With the continuous cooling of the earth, the ground temperature gradually decreases, so the water vapor around the earth begins to condense into small water droplets, which float in the air, converge into clouds, and finally form rain. It is said that about 10 billion years ago, the earth has been raining cats and dogs for tens of thousands of years. Because there were no living things at that time, there was not even a grass on the earth. As a result, the rain washed away the mountain, took away the sediment and dissolved substances, and the turbid water rolled towards the low-lying parts of the earth, forming a primitive ocean. Another viewpoint of Wgx China Children's Resource Network is that, after calculation, the quality of seawater is 282 times greater than that of the atmosphere. Will there be so much water vapor on the primitive earth? Even if there is so much water vapor, where does it come from? So people should look for the source of seawater from the earth itself. According to this view, most of the initial water of the earth exists in the form of rock crystal water. For a period of time after the birth of the earth, the earth was very restless, with cracks and volcanic eruptions everywhere. Therefore, the water in the earth gradually precipitates and gathers on the surface through magmatic activities, or brings high-temperature water vapor into the atmosphere through volcanic activities, and then condenses into rain water, which falls to the surface and flows into the ocean in ocean basins. People can imagine that these two situations have existed at the same time or successively. After hundreds of millions of years of storms, lightning, landslides, land subsidence, flames flying and magma rushing, the ocean finally formed. The original ocean was only slightly salty. Later, due to the large and small currents flowing into the ocean, some substances were dissolved, which increased the chloride and sulfate content in seawater, making the ocean a salty and bitter "cornucopia". Wgx China Children's Resource Network Recently, scientists from the research team of the University of Iowa in the United States put forward a thought-provoking new view: the water on the earth may come from small comets made of ice in space. When they studied thousands of ultraviolet radiation images of the earth's atmosphere sent back by satellites, they found that there were always some small black spots on the disc-shaped earth images, and each small black spot existed for about 2-3 minutes, covering an area of about 2,000 square kilometers. Careful analysis shows that these spots are formed by small comets composed of some invisible ice cubes rushing into the outer atmosphere of the earth and breaking and melting into water vapor. It is estimated that about 20 icy comets with an average diameter of 10 meter enter the earth's atmosphere every minute, and each comet releases about 65438+ million kilograms of water. The earth has been formed for more than 4 billion years, so the increasing water of these small comets is enough to form such a vast ocean today.