How Did Water Form on Earth

If Earth was born a hot and dry planet, the water must have arrived later, after the planet had cooled, presumably brought by icy comets and asteroids from far out in the solar system, which bombarded the young planet, seeding it with their water, some of which stayed on the surface and became our oceans, while the …

How was water formed on Earth?

The new research suggests that Earth’s water came from both rocky material, such as asteroids, and from the vast cloud of dust and gas remaining after the sun’s formation, called the solar nebula. … In the case of Earth’s oceans, the deuterium-to-hydrogen ratio is close to what is found in asteroids.

When did water first appear on Earth?

There is also geological evidence that helps constrain the time frame for liquid water existing on Earth. A sample of pillow basalt (a type of rock formed during an underwater eruption) was recovered from the Isua Greenstone Belt and provides evidence that water existed on Earth 3.8 billion years ago.