Where did earth get its water from?

Earth's water is believed to have originated from multiple sources, including the planet's formation and the impact of water-rich space objects like comets and asteroids.

While some water may have been present in the early Earth, scientists suggest that most of it was delivered later through collisions with water-rich planetesimals.

Here's a more detailed look:

1. Primordial Water:

Some water may have been present in the early Earth's crust and mantle due to the formation of the planet from dust and gas in the solar system.

It's possible that interactions between the magma ocean and a protovolcanic atmosphere, with hydrogen and oxygen, contributed to the production of large amounts of water, reports Carnegie Science.

2. Extraterrestrial Delivery:

Comets and Asteroids:

The most widely accepted theory is that water was brought to Earth by comets and asteroids, especially those from the outer regions of the solar system.

Asteroids:

Carbonaceous asteroids, like those found in the outer asteroid belt, are considered strong candidates for water delivery, as they contain water-ice that could have reacted with minerals to form clays.

Impacts:

These space objects collided with Earth over billions of years, releasing water into the planet's atmosphere and eventually oceans, according to NASA.

Theia's Role:

The giant impact that formed the Moon may have also brought water to Earth, as Theia, the impacting planet, is thought to have originated in the outer solar system.

3. Volcanism:

Volcanic eruptions can also release water vapor into the atmosphere, which then condenses to form rain.