Mystery: When and where did Earth's water come from?

Earth is known as the Blue Planet because of the oceans, which cover more than 70 percent of the surface. While water is essential to life on Earth, the answers to two key questions remain: when and where did Earth's water come from?

Some hypothesize that water came to Earth late, after the planet had formed. But findings from a new study led by scientists at the Woods Hole Oceanographic Institution (WHOI) turn back the clock on evidence of water on Earth.

The answer is that the oceans have always been here, and were not created by a delayed process, as was thought.

One school of thought was that the planets first formed dry, and that the water came later from sources such as comets or wet asteroids, which are composed mostly of ice and gases. From destruction comes formation, they say; the collision of asteroids and giant meteors is destruction; any water molecules that were present as the planets formed evaporated, and the water that exists on Earth today must have arrived hundreds of millions of years later.

But the study's authors focused on a potential source of Earth's water — carbonaceous chondrites, the most primitive meteorites known to date, which formed in the same vortex of dust, rock, ice and gases that created the Sun about 4.6 billion years ago. first, or before the formation of the planets.

In composition, these meteorites mostly resemble the Sun, and scientists think that they contain water, which is why they were taken as candidates for the origin of Earth's water. The study shows that the Earth's water most likely arrived at the same time as the planet itself, so the Earth itself was originally a rock with water on the surface. If this is true, then life on Earth may have started much earlier than previously thought.