How did water form on Earth?

Most of our planet is covered with water. There is no second planet in the solar system with so much liquid water. Where water came from on Earth is not known to modern science, although scientists have put forward two main hypotheses. According to the first hypothesis, water was formed as a result of degassing of the earth’s interior. At the initial stage of the planet’s development, during volcanic eruptions, gases and water vapor entered the primary atmosphere, which condensed, gave the first clouds and rain, according to the hypothesis, it went on for a million years. According to the second hypothesis, the Earth’s water is of cosmic origin. In the past, there were collisions with comets, the nucleus of comets consists of ice, after which melts and water accumulated.