The origin of Earth's water is a long-debated mystery. Some believe it was delivered by comets or asteroids, while others think it formed as Earth itself was developing.
One theory suggests icy comets bombarded early Earth, bringing water. These comets, rich in ice, may have melted and contributed to our oceans and water sources.
Another idea is that asteroids, containing water in minerals, brought it to Earth. As they collided with the planet, the water could have been released over time.
Some scientists believe Earth's water may have originated from materials present when the planet formed. Water may have been trapped in minerals and gradually released.
The solar system's formation may also hold clues. Water could have been part of the gas and dust cloud that formed the Sun and planets, including Earth.
The early Earth was a molten, hostile place. Once the surface cooled, any water that came from space or internal sources would have pooled, creating oceans.
Volcanic activity on early Earth might have released trapped water vapor into the atmosphere, which eventually condensed to form liquid water on the surface.